draft-ietf-taps-transports-usage-05.txt   draft-ietf-taps-transports-usage-06.txt 
TAPS M. Welzl TAPS M. Welzl
Internet-Draft University of Oslo Internet-Draft University of Oslo
Intended status: Informational M. Tuexen Intended status: Informational M. Tuexen
Expires: November 25, 2017 Muenster Univ. of Appl. Sciences Expires: December 26, 2017 Muenster Univ. of Appl. Sciences
N. Khademi N. Khademi
University of Oslo University of Oslo
May 24, 2017 June 24, 2017
On the Usage of Transport Features Provided by IETF Transport Protocols On the Usage of Transport Features Provided by IETF Transport Protocols
draft-ietf-taps-transports-usage-05 draft-ietf-taps-transports-usage-06
Abstract Abstract
This document describes how the transport protocols Transmission This document describes how the transport protocols Transmission
Control Protocol (TCP), MultiPath TCP (MPTCP), Stream Control Control Protocol (TCP), MultiPath TCP (MPTCP), Stream Control
Transmission Protocol (SCTP), User Datagram Protocol (UDP) and Transmission Protocol (SCTP), User Datagram Protocol (UDP) and
Lightweight User Datagram Protocol (UDP-Lite) expose services to Lightweight User Datagram Protocol (UDP-Lite) expose services to
applications and how an application can configure and use the applications and how an application can configure and use the
features that make up these services. It also discusses the service features that make up these services. It also discusses the service
provided by the Low Extra Delay Background Transport (LEDBAT) provided by the Low Extra Delay Background Transport (LEDBAT)
congestion control mechanism. congestion control mechanism. The description results in a set of
transport abstractions that can be exported in a TAPS API.
Status of This Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on November 25, 2017. This Internet-Draft will expire on December 26, 2017.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Pass 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Pass 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Primitives Provided by TCP . . . . . . . . . . . . . . . 5 3.1. Primitives Provided by TCP . . . . . . . . . . . . . . . . 5
3.1.1. Excluded Primitives or Parameters . . . . . . . . . . 9 3.1.1. Excluded Primitives or Parameters . . . . . . . . . . 9
3.2. Primitives Provided by MPTCP . . . . . . . . . . . . . . 9 3.2. Primitives Provided by MPTCP . . . . . . . . . . . . . . . 9
3.3. Primitives Provided by SCTP . . . . . . . . . . . . . . . 10 3.3. Primitives Provided by SCTP . . . . . . . . . . . . . . . 10
3.3.1. Excluded Primitives or Parameters . . . . . . . . . . 18 3.3.1. Excluded Primitives or Parameters . . . . . . . . . . 17
3.4. Primitives Provided by UDP and UDP-Lite . . . . . . . . . 18 3.4. Primitives Provided by UDP and UDP-Lite . . . . . . . . . 18
3.5. The service of LEDBAT . . . . . . . . . . . . . . . . . . 19 3.5. The service of LEDBAT . . . . . . . . . . . . . . . . . . 19
4. Pass 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4. Pass 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.1. CONNECTION Related Primitives . . . . . . . . . . . . . . 21 4.1. CONNECTION Related Primitives . . . . . . . . . . . . . . 21
4.2. DATA Transfer Related Primitives . . . . . . . . . . . . 36 4.2. DATA Transfer Related Primitives . . . . . . . . . . . . . 32
5. Pass 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 5. Pass 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5.1. CONNECTION Related Transport Features . . . . . . . . . . 39 5.1. CONNECTION Related Transport Features . . . . . . . . . . 35
5.2. DATA Transfer Related Transport Features . . . . . . . . 47 5.2. DATA Transfer Related Transport Features . . . . . . . . . 41
5.2.1. Sending Data . . . . . . . . . . . . . . . . . . . . 48 5.2.1. Sending Data . . . . . . . . . . . . . . . . . . . . . 41
5.2.2. Receiving Data . . . . . . . . . . . . . . . . . . . 49 5.2.2. Receiving Data . . . . . . . . . . . . . . . . . . . . 42
5.2.3. Errors . . . . . . . . . . . . . . . . . . . . . . . 50 5.2.3. Errors . . . . . . . . . . . . . . . . . . . . . . . . 43
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 50 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 43
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 51 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 43
8. Security Considerations . . . . . . . . . . . . . . . . . . . 51 8. Security Considerations . . . . . . . . . . . . . . . . . . . 44
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 51 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 44
9.1. Normative References . . . . . . . . . . . . . . . . . . 51 9.1. Normative References . . . . . . . . . . . . . . . . . . . 44
9.2. Informative References . . . . . . . . . . . . . . . . . 54 9.2. Informative References . . . . . . . . . . . . . . . . . . 46
Appendix A. Overview of RFCs used as input for pass 1 . . . . . 55 Appendix A. Overview of RFCs used as input for pass 1 . . . . . . 48
Appendix B. How this document was developed . . . . . . . . . . 55 Appendix B. How this document was developed . . . . . . . . . . . 48
Appendix C. Revision information . . . . . . . . . . . . . . . . 57 Appendix C. Revision information . . . . . . . . . . . . . . . . 49
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 58 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 50
1. Terminology 1. Terminology
Transport Feature: a specific end-to-end feature that the transport Transport Feature: a specific end-to-end feature that the transport
layer provides to an application. Examples include layer provides to an application. Examples include
confidentiality, reliable delivery, ordered delivery, message- confidentiality, reliable delivery, ordered delivery, message-
versus-stream orientation, etc. versus-stream orientation, etc.
Transport Service: a set of Transport Features, without an Transport Service: a set of Transport Features, without an
association to any given framing protocol, which provides a association to any given framing protocol, which provides a
complete service to an application. complete service to an application.
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Event: a primitive that is invoked by a transport endpoint. Event: a primitive that is invoked by a transport endpoint.
Parameter: a value passed between an application and a transport Parameter: a value passed between an application and a transport
protocol by a primitive. protocol by a primitive.
Socket: the combination of a destination IP address and a Socket: the combination of a destination IP address and a
destination port number. destination port number.
Transport Address: the combination of an IP address, transport Transport Address: the combination of an IP address, transport
protocol and the port number used by the transport protocol. protocol and the port number used by the transport protocol.
2. Introduction 2. Introduction
This document presents, in the form of primitives, events and The TAPS working group intends to describe an (abstract) interface
transport features, defined interactions between applications and the for applications to make use of Transport Services, such that
following unicast transport protocols: Transmission Control Protocol applications are no longer directly tied to a specific protocol.
(TCP), MultiPath TCP (MPTCP), Stream Control Transmission Protocol Breaking this strict connection can reduce the effort for an
(SCTP), User Datagram Protocol (UDP), Lightweight User Datagram application programmer, yet attain greater transport flexibility by
Protocol (UDP-Lite). It also defines a primitive to enable/disable pushing complexity into an underlying TAPS system.
and configure the Low Extra Delay Background Transport (LEDBAT)
unicast congestion control mechanism. Transport protocols provide This design process has started with a survey of the services
communication between processes that operate on network endpoints, provided by IETF transport protocols and congestion control
which means that they allow for multiplexing of communication between mechanisms [RFC8095]. The present document and [FJ16] complement
the same IP addresses, and normally this multiplexing is achieved this survey with an in-depth look at the defined interactions between
using port numbers. Port multiplexing is therefore assumed to be applications and the following unicast transport protocols:
always provided and not discussed in this document. Transmission Control Protocol (TCP), MultiPath TCP (MPTCP), Stream
Control Transmission Protocol (SCTP), User Datagram Protocol (UDP),
Lightweight User Datagram Protocol (UDP-Lite). We also define a
primitive to enable/disable and configure the Low Extra Delay
Background Transport (LEDBAT) unicast congestion control mechanism.
This snapshot in time analysis of the IETF transport protocols is
published as an RFC to document the authors' and working group's
analysis, generating a set of transport abstractions that can be
exported in a TAPS API. It provides the basis for the minimal set of
transport services that end systems supporting TAPS should implement
[I-D.draft-gjessing-taps-minset].
The list of primitives, events and transport features in this The list of primitives, events and transport features in this
document is strictly based on the parts of protocol specifications document is strictly based on the parts of protocol specifications
that describe what the protocol provides to an application using it that describe what the protocol provides to an application using it
and how the application interacts with it. Together with an overview and how the application interacts with it. Transport protocols
of the services provided by IETF transport protocols and congestion provide communication between processes that operate on network
control mechanisms [RFC8095] and an analysis of UDP and UDP-Lite endpoints, which means that they allow for multiplexing of
[FJ16], it provides the basis for the minimal set of transport communication between the same IP addresses, and normally this
services that end systems should support multiplexing is achieved using port numbers. Port multiplexing is
[I-D.draft-gjessing-taps-minset]. therefore assumed to be always provided and not discussed in this
document.
Parts of a protocol that are explicitly stated as optional to Parts of a protocol that are explicitly stated as optional to
implement are not covered. Interactions between the application and implement are not covered. Interactions between the application and
a transport protocol that are not directly related to the operation a transport protocol that are not directly related to the operation
of the protocol are also not covered. For example, there are various of the protocol are also not covered. For example, there are various
ways for an application to use socket options to indicate its ways for an application to use socket options to indicate its
interest in receiving certain notifications [RFC6458]. However, for interest in receiving certain notifications [RFC6458]. However, for
the purpose of identifying primitives, events and transport features, the purpose of identifying primitives, events and transport features,
the ability to enable or disable the reception of notifications is the ability to enable or disable the reception of notifications is
irrelevant. Similarly, "one-to-many style sockets" [RFC6458] just irrelevant. Similarly, "one-to-many style sockets" [RFC6458] just
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Some protocols are connection-oriented. Connection-oriented Some protocols are connection-oriented. Connection-oriented
protocols often use an initial call to a specific primitive to open a protocols often use an initial call to a specific primitive to open a
connection before communication can progress, and require connection before communication can progress, and require
communication to be explicitly terminated by issuing another call to communication to be explicitly terminated by issuing another call to
a primitive (usually called "close"). A "connection" is the common a primitive (usually called "close"). A "connection" is the common
state that some transport primitives refer to, e.g., to adjust state that some transport primitives refer to, e.g., to adjust
general configuration settings. Connection establishment, general configuration settings. Connection establishment,
maintenance and termination are therefore used to categorize maintenance and termination are therefore used to categorize
transport primitives of connection-oriented transport protocols in transport primitives of connection-oriented transport protocols in
pass 2 and pass 3. For this purpose, UDP is assumed to be used with pass 2 and pass 3. For this purpose, UDP is assumed to be used with
"connected" sockets, i.e. sockets that are bound to a specific pair "connected" sockets, i.e. sockets that are bound to a specific pair
of addresses and ports [FJ16]. of addresses and ports [FJ16].
3. Pass 1 3. Pass 1
This first iteration summarizes the relevant text parts of the RFCs This first iteration summarizes the relevant text parts of the RFCs
describing the protocols, focusing on what each transport protocol describing the protocols, focusing on what each transport protocol
provides to the application and how it is used (abstract API provides to the application and how it is used (abstract API
descriptions, where they are available). descriptions, where they are available). When presenting primitives,
events and parameters, the use of lower- and upper-case characters is
made uniform for the sake of readability.
3.1. Primitives Provided by TCP 3.1. Primitives Provided by TCP
The initial TCP specification [RFC0793] states: "The Transmission The initial TCP specification [RFC0793] states: "The Transmission
Control Protocol (TCP) is intended for use as a highly reliable host- Control Protocol (TCP) is intended for use as a highly reliable host-
to-host protocol between hosts in packet-switched computer to-host protocol between hosts in packet-switched computer
communication networks, and in interconnected systems of such communication networks, and in interconnected systems of such
networks". Section 3.8 in this specification [RFC0793] further networks". Section 3.8 in this specification [RFC0793] further
specifies the interaction with the application by listing several specifies the interaction with the application by listing several
transport primitives. It is also assumed that an Operating System transport primitives. It is also assumed that an Operating System
provides a means for TCP to asynchronously signal the application; provides a means for TCP to asynchronously signal the application;
the primitives representing such signals are called 'events' in this the primitives representing such signals are called 'events' in this
section. This section describes the relevant primitives. section. This section describes the relevant primitives.
open: this is either active or passive, to initiate a connection or Open: this is either active or passive, to initiate a connection or
listen for incoming connections. All other primitives are listen for incoming connections. All other primitives are
associated with a specific connection, which is assumed to first associated with a specific connection, which is assumed to first
have been opened. An active open call contains a socket. A have been opened. An active open call contains a socket. A
passive open call with a socket waits for a particular connection; passive open call with a socket waits for a particular connection;
alternatively, a passive open call can leave the socket alternatively, a passive open call can leave the socket
unspecified to accept any incoming connection. A fully specified unspecified to accept any incoming connection. A fully specified
passive call can later be made active by calling 'send'. passive call can later be made active by calling 'Send'.
Optionally, a timeout can be specified, after which TCP will abort Optionally, a timeout can be specified, after which TCP will abort
the connection if data has not been successfully delivered to the the connection if data has not been successfully delivered to the
destination (else a default timeout value is used). A procedure destination (else a default timeout value is used). A procedure
for aborting the connection is used to avoid excessive for aborting the connection is used to avoid excessive
retransmissions, and an application is able to control the retransmissions, and an application is able to control the
threshold used to determine the condition for aborting; this threshold used to determine the condition for aborting; this
threshold may be measured in time units or as a count of threshold may be measured in time units or as a count of
retransmission [RFC1122]. This indicates that the timeout could retransmission [RFC1122]. This indicates that the timeout could
also be specified as a count of retransmission. also be specified as a count of retransmission.
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configured when calling open (section 7.1 of [RFC5925]). When configured when calling open (section 7.1 of [RFC5925]). When
authentication is in use, complete TCP segments are authenticated, authentication is in use, complete TCP segments are authenticated,
including the TCP IPv4 pseudoheader, TCP header, and TCP data. including the TCP IPv4 pseudoheader, TCP header, and TCP data.
TCP Fast Open (TFO) [RFC7413] allows to immediately hand over a TCP Fast Open (TFO) [RFC7413] allows to immediately hand over a
message from the active open to the passive open side of a TCP message from the active open to the passive open side of a TCP
connection together with the first message establishment packet connection together with the first message establishment packet
(the SYN). This can be useful for applications that are sensitive (the SYN). This can be useful for applications that are sensitive
to TCP's connection setup delay. TCP implementations MUST NOT use to TCP's connection setup delay. TCP implementations MUST NOT use
TFO by default, but only use TFO if requested explicitly by the TFO by default, but only use TFO if requested explicitly by the
application on a per-service-port basis. more than TCP's maximum application on a per-service-port basis. more than TCP's maximum
segment size (minus options used in the SYN). For the active open segment size (minus options used in the SYN). For the active open
side, it is recommended to change or replace the connect() call in side, it is recommended to change or replace the connect() call in
order to support a user data buffer argument [RFC7413]. For the order to support a user data buffer argument [RFC7413]. For the
passive open side, the application needs to enable the reception passive open side, the application needs to enable the reception
of Fast Open requests, e.g. via a new TCP_FASTOPEN setsockopt() of Fast Open requests, e.g. via a new TCP_FASTOPEN setsockopt()
socket option before listen(). The receiving application must be socket option before listen(). The receiving application must be
prepared to accept duplicates of the TFO message, as the first prepared to accept duplicates of the TFO message, as the first
data written to a socket can be delivered more than once to the data written to a socket can be delivered more than once to the
application on the remote host. application on the remote host.
send: this is the primitive that an application uses to give the Send: this is the primitive that an application uses to give the
local TCP transport endpoint a number of bytes that TCP should local TCP transport endpoint a number of bytes that TCP should
reliably send to the other side of the connection. The URGENT reliably send to the other side of the connection. The 'urgent'
flag, if set, states that the data handed over by this send call flag, if set, states that the data handed over by this send call
is urgent and this urgency should be indicated to the receiving is urgent and this urgency should be indicated to the receiving
process in case the receiving application has not yet consumed all process in case the receiving application has not yet consumed all
non-urgent data preceding it. An optional timeout parameter can non-urgent data preceding it. An optional timeout parameter can
be provided that updates the connection's timeout (see 'open'). be provided that updates the connection's timeout (see 'open').
Additionally, optional parameters allow to indicate the preferred Additionally, optional parameters allow to indicate the preferred
outgoing MKT (current_key) and/or the preferred incoming MKT outgoing MKT (current_key) and/or the preferred incoming MKT
(rnext_key) of a connection (section 7.1 of [RFC5925]). (rnext_key) of a connection (section 7.1 of [RFC5925]).
receive: This primitive allocates a receiving buffer for a provided Receive: This primitive allocates a receiving buffer for a provided
number of bytes. It returns the number of received bytes provided number of bytes. It returns the number of received bytes provided
in the buffer when these bytes have been received and written into in the buffer when these bytes have been received and written into
the buffer by TCP. The application is informed of urgent data via the buffer by TCP. The application is informed of urgent data via
an URGENT flag: if it is on, there is urgent data. If it is off, an 'urgent' flag: if it is on, there is urgent data. If it is
there is no urgent data or this call to 'receive' has returned all off, there is no urgent data or this call to 'receive' has
the urgent data. The application is also informed about the returned all the urgent data. The application is also informed
current_key and rnext_key information carried in a recently about the current_key and rnext_key information carried in a
received segment via an optional parameter (section 7.1 of recently received segment via an optional parameter (section 7.1
[RFC5925]). of [RFC5925]).
close: This primitive closes one side of a connection. It is Close: This primitive closes one side of a connection. It is
semantically equivalent to "I have no more data to send" but does semantically equivalent to "I have no more data to send" but does
not mean "I will not receive any more", as the other side may not mean "I will not receive any more", as the other side may
still have data to send. This call reliably delivers any data still have data to send. This call reliably delivers any data
that has already been given to TCP (and if that fails, 'close' that has already been given to TCP (and if that fails, 'close'
becomes 'abort'). becomes 'abort').
abort: This primitive causes all pending 'send' and 'receive' calls Abort: This primitive causes all pending 'send' and 'receive' calls
to be aborted. A TCP RESET message is sent to the TCP endpoint on to be aborted. A TCP "RESET" message is sent to the TCP endpoint
the other side of the connection [RFC0793]. on the other side of the connection [RFC0793].
close event: TCP uses this primitive to inform an application that Close Event: TCP uses this primitive to inform an application that
the application on the other side has called the 'close' the application on the other side has called the 'close'
primitive, so the local application can also issue a 'close' and primitive, so the local application can also issue a 'close' and
terminate the connection gracefully. See [RFC0793], Section 3.5. terminate the connection gracefully. See [RFC0793], Section 3.5.
abort event: When TCP aborts a connection upon receiving a "Reset" Abort Event: When TCP aborts a connection upon receiving a "RESET"
from the peer, it "advises the user and goes to the CLOSED state." from the peer, it "advises the user and goes to the CLOSED state."
See [RFC0793], Section 3.4. See [RFC0793], Section 3.4.
USER TIMEOUT event: This event is executed when the user timeout User Timeout Event: This event is executed when the user timeout
expires (see 'open') (section 3.9 of [RFC0793]). All queues are expires (see 'open') (section 3.9 of [RFC0793]). All queues are
flushed and the application is informed that the connection had to flushed and the application is informed that the connection had to
be aborted due to user timeout. be aborted due to user timeout.
ERROR_REPORT event: This event informs the application of "soft Error_Report event: This event informs the application of "soft
errors" that can be safely ignored [RFC5461], including the errors" that can be safely ignored [RFC5461], including the
arrival of an ICMP error message or excessive retransmissions arrival of an ICMP error message or excessive retransmissions
(reaching a threshold below the threshold where the connection is (reaching a threshold below the threshold where the connection is
aborted). See section 4.2.4.1 of [RFC1122]. aborted). See section 4.2.4.1 of [RFC1122].
Type-of-Service: Section 4.2.4.2 of the requirements for Internet Type-of-Service: Section 4.2.4.2 of the requirements for Internet
hosts [RFC1122] states that the application layer MUST be able to hosts [RFC1122] states that the application layer MUST be able to
specify the Type-of-Service (TOS) for segments that are sent on a specify the Type-of-Service (TOS) for segments that are sent on a
connection. The application should be able to change the TOS connection. The application should be able to change the TOS
during the connection lifetime, and the TOS value should be passed during the connection lifetime, and the TOS value should be passed
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increase the likelihood of sending a full-sized segment (section increase the likelihood of sending a full-sized segment (section
4.2.3.4 of [RFC1122]). An application can disable the Nagle 4.2.3.4 of [RFC1122]). An application can disable the Nagle
algorithm for an individual connection. algorithm for an individual connection.
User Timeout Option: The User Timeout Option (UTO) [RFC5482] allows User Timeout Option: The User Timeout Option (UTO) [RFC5482] allows
one end of a TCP connection to advertise its current user timeout one end of a TCP connection to advertise its current user timeout
value so that the other end of the TCP connection can adapt its value so that the other end of the TCP connection can adapt its
own user timeout accordingly. In addition to the configurable own user timeout accordingly. In addition to the configurable
value of the User Timeout (see 'send'), there are three per- value of the User Timeout (see 'send'), there are three per-
connection state variables that an application can adjust to connection state variables that an application can adjust to
control the operation of the User Timeout Option (UTO): ADV_UTO is control the operation of the User Timeout Option (UTO): 'adv_uto'
the value of the UTO advertised to the remote TCP peer (default: is the value of the UTO advertised to the remote TCP peer
system-wide default user timeout); ENABLED (default false) is a (default: system-wide default user timeout); 'enabled' (default
boolean-type flag that controls whether the UTO option is enabled false) is a boolean-type flag that controls whether the UTO option
for a connection. This applies to both sending and receiving. is enabled for a connection. This applies to both sending and
CHANGEABLE is a boolean-type flag (default true) that controls receiving. 'changeable' is a boolean-type flag (default true) that
whether the user timeout may be changed based on a UTO option controls whether the user timeout may be changed based on a UTO
received from the other end of the connection. CHANGEABLE becomes option received from the other end of the connection. 'changeable'
false when an application explicitly sets the user timeout (see becomes false when an application explicitly sets the user timeout
'send'). (see 'send').
Set / Get Authentication Parameters: The preferred outgoing MKT Set / Get Authentication Parameters: The preferred outgoing MKT
(current_key) and/or the preferred incoming MKT (rnext_key) of a (current_key) and/or the preferred incoming MKT (rnext_key) of a
connection can be configured. Information about current_key and connection can be configured. Information about current_key and
rnext_key carried in a recently received segment can be retrieved rnext_key carried in a recently received segment can be retrieved
(section 7.1 of [RFC5925]). (section 7.1 of [RFC5925]).
3.1.1. Excluded Primitives or Parameters 3.1.1. Excluded Primitives or Parameters
The 'open' primitive can be handed optional Precedence or security/ The 'open' primitive can be handed optional Precedence or security/
compartment information [RFC0793], but this was not included here compartment information [RFC0793], but this was not included here
because it is mostly irrelevant today [RFC7414]. because it is mostly irrelevant today [RFC7414].
The 'status' primitive was not included because the initial TCP The 'Status' primitive was not included because the initial TCP
specification describes this primitive as "implementation dependent" specification describes this primitive as "implementation dependent"
and states that it "could be excluded without adverse effect" and states that it "could be excluded without adverse effect"
[RFC0793]. Moreover, while a data block containing specific [RFC0793]. Moreover, while a data block containing specific
information is described, it is also stated that not all of this information is described, it is also stated that not all of this
information may always be available. While 'status' SHOULD be information may always be available. While 'Status' SHOULD be
augmented to allow the MKTs of a current or pending connection to be augmented to allow the MKTs of a current or pending connection to be
read (for confirmation), the same information is also available via read (for confirmation), the same information is also available via
'receive', which MUST be augmented with that functionality [RFC5925]. 'Receive', which MUST be augmented with that functionality [RFC5925].
The 'send' primitive includes an optional PUSH flag which, if set, The 'Send' primitive includes an optional 'push' flag which, if set,
requires data to be promptly transmitted to the receiver without requires data to be promptly transmitted to the receiver without
delay [RFC0793]; the 'receive' primitive described in can (under some delay [RFC0793]; the 'Receive' primitive described in can (under some
conditions) yield the status of the PUSH flag. Because PUSH conditions) yield the status of the 'push' flag. Because "push"
functionality is optional to implement for both the 'send' and functionality is optional to implement for both the 'send' and
'receive' primitives [RFC1122], this functionality is not included 'receive' primitives [RFC1122], this functionality is not included
here. The requirements for Internet hosts [RFC1122] also introduce here. The requirements for Internet hosts [RFC1122] also introduce
keep-alives to TCP, but these are optional to implement and hence not keep-alives to TCP, but these are optional to implement and hence not
considered here. The same document also describes that "some TCP considered here. The same document also describes that "some TCP
implementations have included a FLUSH call", indicating that this implementations have included a FLUSH call", indicating that this
call is also optional to implement. It is therefore not considered call is also optional to implement. It is therefore not considered
here. here.
3.2. Primitives Provided by MPTCP 3.2. Primitives Provided by MPTCP
skipping to change at page 10, line 9 skipping to change at page 10, line 21
level of backward compatibility with existing TCP APIs, so that level of backward compatibility with existing TCP APIs, so that
existing applications can use the newer merely by upgrading the existing applications can use the newer merely by upgrading the
operating systems of the end hosts." As such, the primitives operating systems of the end hosts." As such, the primitives
provided by MPTCP are equivalent to the ones provided by TCP. provided by MPTCP are equivalent to the ones provided by TCP.
Nevertheless, the MPTCP RFCs [RFC6824] and [RFC6897] clarify some Nevertheless, the MPTCP RFCs [RFC6824] and [RFC6897] clarify some
parts of TCP's primitives with respect to MPTCP and add some parts of TCP's primitives with respect to MPTCP and add some
extensions for better control on MPTCP's subflows. Hereafter is a extensions for better control on MPTCP's subflows. Hereafter is a
list of the clarifications and extensions the above cited RFCs list of the clarifications and extensions the above cited RFCs
provide to TCP's primitives. provide to TCP's primitives.
open: "An application should be able to request to turn on or turn Open: "An application should be able to request to turn on or turn
off the usage of MPTCP" [RFC6897]. This functionality can be off the usage of MPTCP" [RFC6897]. This functionality can be
provided through a socket-option called TCP_MULTIPATH_ENABLE. provided through a socket-option called 'tcp_multipath_enable'.
Further, MPTCP must be disabled in case the application is binding Further, MPTCP must be disabled in case the application is binding
to a specific address [RFC6897]. to a specific address [RFC6897].
send/receive: The sending and receiving of data does not require any Send/Receive: The sending and receiving of data does not require any
changes to the application when MPTCP is being used [RFC6824]. changes to the application when MPTCP is being used [RFC6824].
The MPTCP-layer will "take one input data stream from an The MPTCP-layer will "take one input data stream from an
application, and split it into one or more subflows, with application, and split it into one or more subflows, with
sufficient control information to allow it to be reassembled and sufficient control information to allow it to be reassembled and
delivered reliably and in order to the recipient application." delivered reliably and in order to the recipient application."
The use of the Urgent-Pointer is special in MPTCP [RFC6824]: "a The use of the Urgent Pointer is special in MPTCP [RFC6824]: "a
TCP subflow MUST NOT use the Urgent Pointer to interrupt an TCP subflow MUST NOT use the Urgent Pointer to interrupt an
existing mapping." existing mapping."
address and subflow management: MPTCP uses different addresses and Address and Subflow Management: MPTCP uses different addresses and
allows a host to announce these addresses as part of the protocol. allows a host to announce these addresses as part of the protocol.
The MPTCP API Considerations RFC [RFC6897] says "An application The MPTCP API Considerations RFC [RFC6897] says "An application
should be able to restrict MPTCP to binding to a given set of should be able to restrict MPTCP to binding to a given set of
addresses" and thus allows applications to limit the set of addresses" and thus allows applications to limit the set of
addresses that are being used by MPTCP. Further, "An application addresses that are being used by MPTCP. Further, "An application
should be able to obtain information on the pairs of addresses should be able to obtain information on the pairs of addresses
used by the MPTCP subflows". used by the MPTCP subflows".
3.3. Primitives Provided by SCTP 3.3. Primitives Provided by SCTP
TCP has a number of limitations that SCPT removes (section 1.1 of TCP has a number of limitations that SCPT removes (section 1.1 of
[RFC4960]). The following three removed limitations directly [RFC4960]). The following three removed limitations directly
translate into transport features that are visible to an application translate into transport features that are visible to an application
using SCTP: 1) it allows for preservation of message delineations; 2) using SCTP: 1) it allows for preservation of message delineations; 2)
these messages, while reliably transferred, do not require to be in these messages, do not require to be in order or reliably transferred
order unless the application wants it; 3) multi-homing is supported. unless the application wants it; 3) multi-homing is supported. In
In SCTP, connections are called "associations" and they can be SCTP, connections are called "associations" and they can be between
between not only two (as in TCP) but multiple addresses at each not only two (as in TCP) but multiple addresses at each endpoint.
endpoint.
Section 10 of the SCTP base protocol specification [RFC4960] Section 10 of the SCTP base protocol specification [RFC4960]
specifies the interaction with the application (which this RFC calls specifies the interaction with the application (which this RFC calls
the "Upper Layer Protocol" (ULP)). It is assumed that the Operating the "Upper Layer Protocol" (ULP)). It is assumed that the Operating
System provides a means for SCTP to asynchronously signal the System provides a means for SCTP to asynchronously signal the
application; the primitives representing such signals are called application; the primitives representing such signals are called
'events' in this section. Here, we describe the relevant primitives. 'events' in this section. Here, we describe the relevant primitives.
In addition to the abstract API described in the section 10 of the In addition to the abstract API described in the section 10 of the
SCTP base protocol specification [RFC4960], an extension to the SCTP base protocol specification [RFC4960], an extension to the
socket API is described in [RFC6458]. This covers the functionality socket API is described in [RFC6458]. This covers the functionality
of the base protocol [RFC4960] and some of its extensions [RFC3758], of the base protocol [RFC4960] and some of its extensions [RFC3758],
[RFC4895], [RFC5061]. For other protocol extensions [RFC6525], [RFC4895], [RFC5061]. For other protocol extensions [RFC6525],
[RFC6951], [RFC7053], [RFC7496], [RFC7829], [RFC6951], [RFC7053], [RFC7496], [RFC7829],
[I-D.ietf-tsvwg-sctp-ndata], the corresponding extensions of the [I-D.ietf-tsvwg-sctp-ndata], the corresponding extensions of the
socket API are specified in these protocol specifications. The socket API are specified in these protocol specifications. The
functionality exposed to the ULP through the all these APIs is functionality exposed to the ULP through the all these APIs is
considered here. considered here.
The abstract API contains a "SETPROTOCOLPARAMETERS" primitive that The abstract API contains a 'SetProtocolParameters' primitive that
allows to adjust elements of a parameter list [RFC4960]; it is stated allows to adjust elements of a parameter list [RFC4960]; it is stated
that SCTP implementations "may allow ULP to customize some of these that SCTP implementations "may allow ULP to customize some of these
protocol parameters", indicating that none of the elements of this protocol parameters", indicating that none of the elements of this
parameter list are mandatory to make ULP-configurable. Thus, we only parameter list are mandatory to make ULP-configurable. Thus, we only
consider the parameters in the abstract API that are also covered in consider the parameters in the abstract API that are also covered in
one of the other RFCs listed above, which leads us to exclude the one of the other RFCs listed above, which leads us to exclude the
parameters RTO.Alpha, RTO.Beta and HB.Max.Burst. For clarity, we parameters RTO.Alpha, RTO.Beta and HB.Max.Burst. For clarity, we
also replace "SETPROTOCOLPARAMETERS" itself with primitives that also replace 'SetProtocolParameters' itself with primitives that
adjust parameters or groups of parameters which fit together. adjust parameters or groups of parameters that fit together.
Initialize: Initialize creates a local SCTP instance that it binds Initialize: Initialize creates a local SCTP instance that it binds
to a set of local addresses (and, if provided, a local port to a set of local addresses (and, if provided, a local port
number) [RFC4960]. Initialize needs to be called only once per number) [RFC4960]. Initialize needs to be called only once per
set of local addresses. A number of per-association set of local addresses. A number of per-association
initialization parameters can be used when an association is initialization parameters can be used when an association is
created, but before it is connected (via the primitive 'Associate' created, but before it is connected (via the primitive 'Associate'
below): the maximum number of inbound streams the application is below): the maximum number of inbound streams the application is
prepared to support, the maximum number of attempts to be made prepared to support, the maximum number of attempts to be made
when sending the INIT (the first message of association when sending the INIT (the first message of association
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that multiple paths can later be used. One of the returned that multiple paths can later be used. One of the returned
sockets will be selected by the local endpoint as default primary sockets will be selected by the local endpoint as default primary
path for sending SCTP packets to this peer, but this choice can be path for sending SCTP packets to this peer, but this choice can be
changed by the application using the list of destination changed by the application using the list of destination
addresses. Associate is also given the number of outgoing streams addresses. Associate is also given the number of outgoing streams
to request and optionally returns the number of negotiated to request and optionally returns the number of negotiated
outgoing streams. An optional parameter of 32 bits, the outgoing streams. An optional parameter of 32 bits, the
adaptation layer indication, can be provided [RFC5061]. If adaptation layer indication, can be provided [RFC5061]. If
authenticated chunks are used, the chunk types required to be sent authenticated chunks are used, the chunk types required to be sent
authenticated by the peer can be provided [RFC4895]. A authenticated by the peer can be provided [RFC4895]. A
'SCTP_CANT_STR_ASSOC' notification is used to inform the 'SCTP_Cant_Str_Assoc' notification is used to inform the
application of a failure to create an association [RFC6458]. An application of a failure to create an association [RFC6458]. An
application could use sendto() or sendmsg() to implicitly setup an application could use sendto() or sendmsg() to implicitly setup an
association, thereby handing over a message that SCTP might send association, thereby handing over a message that SCTP might send
during the association setup phase [RFC6458]. Note that this during the association setup phase [RFC6458]. Note that this
mechanism is different from TCP's TFO mechanism: the message would mechanism is different from TCP's TFO mechanism: the message would
arrive only once, after at least one RTT, as it is sent together arrive only once, after at least one RTT, as it is sent together
with the third message exchanged during association setup, the with the third message exchanged during association setup, the
COOKIE-ECHO chunk). COOKIE-ECHO chunk).
Send: This sends a message of a certain length in bytes over an Send: This sends a message of a certain length in bytes over an
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of the user message provided [RFC7053]. Another advisory flag of the user message provided [RFC7053]. Another advisory flag
indicates whether the application prefers to avoid bundling user indicates whether the application prefers to avoid bundling user
data with other outbound DATA chunks (i.e., in the same packet). data with other outbound DATA chunks (i.e., in the same packet).
A payload protocol-id can be provided to pass a value that A payload protocol-id can be provided to pass a value that
indicates the type of payload protocol data to the peer. If indicates the type of payload protocol data to the peer. If
authenticated chunks are used, the key identifier for authenticated chunks are used, the key identifier for
authenticating DATA chunks can be provided [RFC4895]. authenticating DATA chunks can be provided [RFC4895].
Receive: Messages are received from an association, and optionally a Receive: Messages are received from an association, and optionally a
stream within the association, with their size returned. The stream within the association, with their size returned. The
application is notified of the availability of data via a DATA application is notified of the availability of data via a 'Data
ARRIVE notification. If the sender has included a payload Arrive' notification. If the sender has included a payload
protocol-id, this value is also returned. If the received message protocol-id, this value is also returned. If the received message
is only a partial delivery of a whole message, a partial flag will is only a partial delivery of a whole message, a partial flag will
indicate so, in which case the stream id and a stream sequence indicate so, in which case the stream id and a stream sequence
number are provided to the application. A delivery number lets number are provided to the application. A delivery number lets
the application detect reordering. the application detect reordering.
Shutdown: This primitive gracefully closes an association, reliably Shutdown: This primitive gracefully closes an association, reliably
delivering any data that has already been handed over to SCTP. A delivering any data that has already been handed over to SCTP. A
parameter lets the application control whether further receive or parameter lets the application control whether further receive or
send operations or both are disabled when the call is issued. A send operations or both are disabled when the call is issued. A
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was aborted. Optionally, an abort reason to be passed to the peer was aborted. Optionally, an abort reason to be passed to the peer
may be provided by the application. A return code informs about may be provided by the application. A return code informs about
success or failure of this procedure. success or failure of this procedure.
Change Heartbeat / Request Heartbeat: This allows the application to Change Heartbeat / Request Heartbeat: This allows the application to
enable/disable heartbeats and optionally specify a heartbeat enable/disable heartbeats and optionally specify a heartbeat
frequency as well as requesting a single heartbeat to be carried frequency as well as requesting a single heartbeat to be carried
out upon a function call, with a notification about success or out upon a function call, with a notification about success or
failure of transmitting the HEARTBEAT chunk to the destination. failure of transmitting the HEARTBEAT chunk to the destination.
Configure Max. Retransmissions of an Association: The parameter Asso Configure Max. Retransmissions of an Association: The parameter
ciation.Max.Retrans [RFC4960] (called "sasoc_maxrxt" in the SCTP Association.Max.Retrans [RFC4960] (called "sasoc_maxrxt" in the
socket API extensions [RFC6458]), allows to configure the number SCTP socket API extensions [RFC6458]), allows to configure the
of unsuccessful retransmissions after which an entire association number of unsuccessful retransmissions after which an entire
is considered as failed; this should invoke a COMMUNICATION LOST association is considered as failed; this should invoke a
notification. 'Communication Lost' notification.
Set Primary: This allows to set a new primary default path for an Set Primary: This allows to set a new primary default path for an
association by providing a socket. Optionally, a default source association by providing a socket. Optionally, a default source
address to be used in IP datagrams can be provided. address to be used in IP datagrams can be provided.
Change Local Address / Set Peer Primary: This allows an endpoint to Change Local Address / Set Peer Primary: This allows an endpoint to
add/remove local addresses to/from an association. In addition, add/remove local addresses to/from an association. In addition,
the peer can be given a hint which address to use as the primary the peer can be given a hint which address to use as the primary
address [RFC5061]. address [RFC5061].
Configure Path Switchover: The abstract API contains a primitive Configure Path Switchover: The abstract API contains a primitive
called SET FAILURE THRESHOLD [RFC4960]. This configures the called 'Set Failure Threshold' [RFC4960]. This configures the
parameter "Path.Max.Retrans", which determines after how many parameter "Path.Max.Retrans", which determines after how many
retransmissions a particular transport address is considered as retransmissions a particular transport address is considered as
unreachable. If there are more transport addresses available in unreachable. If there are more transport addresses available in
an association, reaching this limit will invoke a path switchover. an association, reaching this limit will invoke a path switchover.
An extension called "SCTP-PF" adds a concept of "Potentially An extension called "SCTP-PF" adds a concept of "Potentially
Failed" (PF) paths to this method [RFC7829]. When a path is in PF Failed" (PF) paths to this method [RFC7829]. When a path is in PF
state, SCTP will not entirely give up sending on that path, but it state, SCTP will not entirely give up sending on that path, but it
will preferably send data on other active paths if such paths are will preferably send data on other active paths if such paths are
available. Entering the PF state is done upon exceeding a available. Entering the PF state is done upon exceeding a
configured maximum number of retransmissions. Thus, for all paths configured maximum number of retransmissions. Thus, for all paths
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Set Stream Scheduler: This allows to select a stream scheduler per Set Stream Scheduler: This allows to select a stream scheduler per
association, with a choice of: First Come First Serve, Round association, with a choice of: First Come First Serve, Round
Robin, Round Robin per Packet, Priority Based, Fair Bandwidth, Robin, Round Robin per Packet, Priority Based, Fair Bandwidth,
Weighted Fair Queuing [I-D.ietf-tsvwg-sctp-ndata]. Weighted Fair Queuing [I-D.ietf-tsvwg-sctp-ndata].
Configure Stream Scheduler: This allows to change a parameter per Configure Stream Scheduler: This allows to change a parameter per
stream for the schedulers: a priority value for the Priority Based stream for the schedulers: a priority value for the Priority Based
scheduler and a weight for the Weighted Fair Queuing scheduler. scheduler and a weight for the Weighted Fair Queuing scheduler.
Enable/disable NODELAY: This turns on/off any Nagle-like algorithm Enable / Disable NoDelay: This turns on/off any Nagle-like algorithm
for an association [RFC6458]. for an association [RFC6458].
Configure send buffer size: This controls the amount of data SCTP Configure Send Buffer Size: This controls the amount of data SCTP
may have waiting in internal buffers to be sent or retransmitted may have waiting in internal buffers to be sent or retransmitted
[RFC6458]. [RFC6458].
Configure receive buffer size: This sets the receive buffer size in Configure Receive Buffer Size: This sets the receive buffer size in
octets, thereby controlling the receiver window for an association octets, thereby controlling the receiver window for an association
[RFC6458]. [RFC6458].
Configure message fragmentation: If a user message causes an SCTP Configure Message Fragmentation: If a user message causes an SCTP
packet to exceed the maximum fragmentation size (which can be packet to exceed the maximum fragmentation size (which can be
provided by the application, and is otherwise the PMTU size), then provided by the application, and is otherwise the PMTU size), then
the message will be fragmented by SCTP. Disabling message the message will be fragmented by SCTP. Disabling message
fragmentation will produce an error instead of fragmenting the fragmentation will produce an error instead of fragmenting the
message [RFC6458]. message [RFC6458].
Configure Path MTU Discovery: Path MTU Discovery can be enabled or Configure Path MTU Discovery: Path MTU Discovery can be enabled or
disabled per peer address of an association (section 8.1.12 of disabled per peer address of an association (section 8.1.12 of
[RFC6458]). When it is enabled, the current Path MTU value can be [RFC6458]). When it is enabled, the current Path MTU value can be
obtained. When it is disabled, the Path MTU to be used can be obtained. When it is disabled, the Path MTU to be used can be
controlled by the application. controlled by the application.
Configure delayed SACK timer: The time before sending a SACK can be Configure Delayed SACK Timer: The time before sending a SACK can be
adjusted; delaying SACKs can be disabled; the number of packets adjusted; delaying SACKs can be disabled; the number of packets
that must be received before a SACK is sent without waiting for that must be received before a SACK is sent without waiting for
the delay timer to expire can be configured [RFC6458]. the delay timer to expire can be configured [RFC6458].
Set Cookie life value: The Cookie life value can be adjusted Set Cookie Life Value: The Cookie life value can be adjusted
(section 8.1.2 of [RFC6458]). "Valid.Cookie.Life" is also one of (section 8.1.2 of [RFC6458]). "Valid.Cookie.Life" is also one of
the parameters that is potentially adjustable with the parameters that is potentially adjustable with
SETPROTOCOLPARAMETERS [RFC4960]. 'SetProtocolParameters' [RFC4960].
Set maximum burst: The maximum burst of packets that can be emitted Set Maximum Burst: The maximum burst of packets that can be emitted
by a particular association (default 4, and values above 4 are by a particular association (default 4, and values above 4 are
optional to implement) can be adjusted (section 8.1.2 of optional to implement) can be adjusted (section 8.1.2 of
[RFC6458]). "Max.Burst" is also one of the parameters that is [RFC6458]). "Max.Burst" is also one of the parameters that is
potentially adjustable with SETPROTOCOLPARAMETERS [RFC4960]. potentially adjustable with 'SetProtocolParameters' [RFC4960].
Configure RTO calculation: The abstract API contains the following Configure RTO Calculation: The abstract API contains the following
adjustable parameters: RTO.Initial; RTO.Min; RTO.Max; RTO.Alpha; adjustable parameters: RTO.Initial; RTO.Min; RTO.Max; RTO.Alpha;
RTO.Beta. Only the initial, minimum and maximum RTO are also RTO.Beta. Only the initial, minimum and maximum RTO are also
described as configurable in the SCTP sockets API extensions described as configurable in the SCTP sockets API extensions
[RFC6458]. [RFC6458].
Set DSCP value: The DSCP value can be set per peer address of an Set DSCP Value: The DSCP value can be set per peer address of an
association (section 8.1.12 of [RFC6458]). association (section 8.1.12 of [RFC6458]).
Set IPv6 flow label: The flow label field can be set per peer Set IPv6 Flow Label: The flow label field can be set per peer
address of an association (section 8.1.12 of [RFC6458]). address of an association (section 8.1.12 of [RFC6458]).
Set Partial Delivery Point: This allows to specify the size of a Set Partial Delivery Point: This allows to specify the size of a
message where partial delivery will be invoked. Setting this to a message where partial delivery will be invoked. Setting this to a
lower value will cause partial deliveries to happen more often lower value will cause partial deliveries to happen more often
[RFC6458]. [RFC6458].
COMMUNICATION UP notification: When a lost communication to an Communication Up Notification: When a lost communication to an
endpoint is restored or when SCTP becomes ready to send or receive endpoint is restored or when SCTP becomes ready to send or receive
user messages, this notification informs the application process user messages, this notification informs the application process
about the affected association, the type of event that has about the affected association, the type of event that has
occurred, the complete set of sockets of the peer, the maximum occurred, the complete set of sockets of the peer, the maximum
number of allowed streams and the inbound stream count (the number number of allowed streams and the inbound stream count (the number
of streams the peer endpoint has requested). If interleaving is of streams the peer endpoint has requested). If interleaving is
supported by both endpoints, this information is also included in supported by both endpoints, this information is also included in
this notification. this notification.
RESTART notification: When SCTP has detected that the peer has Restart Notification: When SCTP has detected that the peer has
restarted, this notification is passed to the upper layer restarted, this notification is passed to the upper layer
[RFC6458]. [RFC6458].
DATA ARRIVE notification: When a message is ready to be retrieved Data Arrive Notification: When a message is ready to be retrieved
via the Receive primitive, the application is informed by this via the 'Receive' primitive, the application is informed by this
notification. notification.
SEND FAILURE notification / Receive Unsent Message / Receive Send Failure Notification / Receive Unsent Message / Receive
Unacknowledged Message: Unacknowledged Message: When a message cannot be delivered via an
When a message cannot be delivered via an association, the sender association, the sender can be informed about it and learn whether
can be informed about it and learn whether the message has just the message has just not been acknowledged or (e.g. in case of
not been acknowledged or (e.g. in case of lifetime expiry) if it lifetime expiry) if it has not even been sent. This can also
has not even been sent. This can also inform the sender that a inform the sender that a part of the message has been successfully
part of the message has been successfully delivered. delivered.
NETWORK STATUS CHANGE notification: The NETWORK STATUS CHANGE Network Status Change Notification: This informs the application
notification informs the application about a socket becoming about a socket becoming active/inactive [RFC4960] or "Potentially
active/inactive [RFC4960] or "Potentially Failed" [RFC7829]. Failed" [RFC7829].
COMMUNICATION LOST notification: When SCTP loses communication to an Communication Lost Notification: When SCTP loses communication to an
endpoint (e.g. via Heartbeats or excessive retransmission) or endpoint (e.g. via Heartbeats or excessive retransmission) or
detects an abort, this notification informs the application detects an abort, this notification informs the application
process of the affected association and the type of event (failure process of the affected association and the type of event (failure
OR termination in response to a shutdown or abort request). OR termination in response to a shutdown or abort request).
SHUTDOWN COMPLETE notification: When SCTP completes the shutdown Shutdown Complete Notification: When SCTP completes the shutdown
procedures, this notification is passed to the upper layer, procedures, this notification is passed to the upper layer,
informing it about the affected assocation. informing it about the affected assocation.
AUTHENTICATION notification: When SCTP wants to notify the upper Authentication Notification: When SCTP wants to notify the upper
layer regarding the key management related to authenticated chunks layer regarding the key management related to authenticated chunks
[RFC4895], this notification is passed to the upper layer. [RFC4895], this notification is passed to the upper layer.
ADAPTATION LAYER INDICATION notification: When SCTP completes the Adaptation Layer Indication Notification: When SCTP completes the
association setup and the peer provided an adaptation layer association setup and the peer provided an adaptation layer
indication, this is passed to the upper layer [RFC5061], indication, this is passed to the upper layer [RFC5061],
[RFC6458]. [RFC6458].
STREAM RESET notification: When SCTP completes the procedure for Stream Reset Notification: When SCTP completes the procedure for
resetting streams [RFC6525], this notification is passed to the resetting streams [RFC6525], this notification is passed to the
upper layer, informing it about the result. upper layer, informing it about the result.
ASSOCIATION RESET notification: When SCTP completes the association Assocation Reset Notification: When SCTP completes the association
reset procedure [RFC6525], this notification is passed to the reset procedure [RFC6525], this notification is passed to the
upper layer, informing it about the result. upper layer, informing it about the result.
STREAM CHANGE notification: When SCTP completes the procedure used Stream Change Notification: When SCTP completes the procedure used
to increase the number of streams [RFC6525], this notification is to increase the number of streams [RFC6525], this notification is
passed to the upper layer, informing it about the result. passed to the upper layer, informing it about the result.
SENDER DRY notification: When SCTP has no more user data to send or Sender Dry Notification: When SCTP has no more user data to send or
retransmit on a particular association, this notification is retransmit on a particular association, this notification is
passed to the upper layer [RFC6458]. passed to the upper layer [RFC6458].
PARTIAL DELIVERY ABORTED notification: When a receiver has begun to Partial Delivery Aborted Notification: When a receiver has begun to
receive parts of a user message but the delivery of this message receive parts of a user message but the delivery of this message
is then aborted, this notification is passed to the upper layer is then aborted, this notification is passed to the upper layer
(section 6.1.7 of [RFC6458]). (section 6.1.7 of [RFC6458]).
3.3.1. Excluded Primitives or Parameters 3.3.1. Excluded Primitives or Parameters
The 'Receive' primitive can return certain additional information, The 'Receive' primitive can return certain additional information,
but this is optional to implement and therefore not considered. With but this is optional to implement and therefore not considered. With
a COMMUNICATION LOST notification, some more information may a 'Communication Lost' notification, some more information may
optionally be passed to the application (e.g., identification to optionally be passed to the application (e.g., identification to
retrieve unsent and unacknowledged data). SCTP "can invoke" a retrieve unsent and unacknowledged data). SCTP "can invoke" a
COMMUNICATION ERROR notification and "may send" a RESTART 'Communication Error' notification and "may send" a 'Restart'
notification, making these two notifications optional to implement. notification, making these two notifications optional to implement.
The list provided under 'Status' includes "etc", indicating that more The list provided under 'Status' includes "etc", indicating that more
information could be provided. The primitive 'Get SRTT Report' information could be provided. The primitive 'Get SRTT Report'
returns information that is included in the information that 'Status' returns information that is included in the information that 'Status'
provides and is therefore not discussed. The 'Destroy SCTP Instance' provides and is therefore not discussed. The 'Destroy SCTP Instance'
API function was excluded: it erases the SCTP instance that was API function was excluded: it erases the SCTP instance that was
created by 'Initialize', but is not a Primitive as defined in this created by 'Initialize', but is not a Primitive as defined in this
document because it does not relate to a transport feature. The document because it does not relate to a transport feature. The
SHUTDOWN EVENT informs an application that the peer has sent a 'Shutdown' event informs an application that the peer has sent a
SHUTDOWN, and hence no further data should be sent on this socket SHUTDOWN, and hence no further data should be sent on this socket
(section 6.1 of [RFC6458]). However, if an application would try to (section 6.1 of [RFC6458]). However, if an application would try to
send data on the socket, it would get an error message anyway; thus, send data on the socket, it would get an error message anyway; thus,
this event is classified as "just affecting the application this event is classified as "just affecting the application
programming style, not how the underlying protocol operates" and not programming style, not how the underlying protocol operates" and not
included here. included here.
3.4. Primitives Provided by UDP and UDP-Lite 3.4. Primitives Provided by UDP and UDP-Lite
The initial UDP specification [RFC0768] states: "This User Datagram The initial UDP specification [RFC0768] states: "This User Datagram
skipping to change at page 20, line 4 skipping to change at page 19, line 29
timestamps and acknowledging data frequently. LEDBAT can be used timestamps and acknowledging data frequently. LEDBAT can be used
with TCP, Stream Control Transmission Protocol (SCTP), and Datagram with TCP, Stream Control Transmission Protocol (SCTP), and Datagram
Congestion Control Protocol (DCCP), with appropriate extensions where Congestion Control Protocol (DCCP), with appropriate extensions where
necessary; and it can be used with proprietary application protocols, necessary; and it can be used with proprietary application protocols,
such as those built on top of UDP for peer-to- peer (P2P) such as those built on top of UDP for peer-to- peer (P2P)
applications." At the time of writing, the appropriate extensions applications." At the time of writing, the appropriate extensions
for TCP, SCTP or DCCP do not exist. for TCP, SCTP or DCCP do not exist.
A numer of configurable parameters exist in the LEDBAT specification: A numer of configurable parameters exist in the LEDBAT specification:
TARGET, which is the queuing delay target at which LEDBAT tries to TARGET, which is the queuing delay target at which LEDBAT tries to
operate, must be set to 100ms or less. ALLOWED_INCREASE (should be operate, must be set to 100ms or less. 'allowed_increase' (should be
1, must be greater than 0) limits the speed at which LEDBAT increases 1, must be greater than 0) limits the speed at which LEDBAT increases
its rate. GAIN, which MUST be set to 1 or less to avoid a faster its rate. 'gain', which MUST be set to 1 or less to avoid a faster
ramp-up than TCP Reno, determines how quickly the sender responds to ramp-up than TCP Reno, determines how quickly the sender responds to
changes in queueing delay. Implementations may divide GAIN into two changes in queueing delay. Implementations may divide 'gain' into
parameters, one for increase and a possibly larger one for decrease. two parameters, one for increase and a possibly larger one for
We call these parameters GAIN_INC and GAIN_DEC here. BASE_HISTORY is decrease. We call these parameters 'Gain_Inc' and 'Gain_Dec' here.
the size of the list of measured base delays, and SHOULD be 10. This 'Base_History' is the size of the list of measured base delays, and
list can be filtered using a FILTER() function which is not SHOULD be 10. This list can be filtered using a 'Filter' function
prescribed [RFC6817], yielding a list of size CURRENT_FILTER. The which is not prescribed [RFC6817], yielding a list of size
initial and minimum congestion windows, INIT_CWND and MIN_CWND, 'Current_Filter'. The initial and minimum congestion windows,
should both be 2. 'Init_CWND' and 'Min_CWND', should both be 2.
Regarding which of these parameters should be under control of an Regarding which of these parameters should be under control of an
application, the possible range goes from exposing nothing on the one application, the possible range goes from exposing nothing on the one
hand, to considering everything that is not prescribed with a MUST in hand, to considering everything that is not prescribed with a MUST in
the specification as a parameter on the other hand. Function the specification as a parameter on the other hand. Function
implementations are not provided as a parameter to any of the implementations are not provided as a parameter to any of the
transport protocols discussed here, and hence we do not regard the transport protocols discussed here, and hence we do not regard the
FILTER() function as a parameter. However, to avoid unnecessarily 'Filter' function as a parameter. However, to avoid unnecessarily
limiting future implementations, we consider all other parameters limiting future implementations, we consider all other parameters
above as tunable parameters that should be exposed. above as tunable parameters that should be exposed.
4. Pass 2 4. Pass 2
This pass categorizes the primitives from pass 1 based on whether This pass categorizes the primitives from pass 1 based on whether
they relate to a connection or to data transmission. Primitives are they relate to a connection or to data transmission. Primitives are
presented following the nomenclature presented following the nomenclature
"CATEGORY.[SUBCATEGORY].PRIMITIVENAME.PROTOCOL". The CATEGORY can be "CATEGORY.[SUBCATEGORY].PRIMITIVENAME.PROTOCOL". The CATEGORY can be
CONNECTION or DATA. Within the CONNECTION category, ESTABLISHMENT, CONNECTION or DATA. Within the CONNECTION category, ESTABLISHMENT,
skipping to change at page 20, line 46 skipping to change at page 20, line 24
PROTOCOL name "UDP(-Lite)" is used when primitives are equivalent for PROTOCOL name "UDP(-Lite)" is used when primitives are equivalent for
UDP and UDP-Lite; the PROTOCOL name "TCP" refers to both TCP and UDP and UDP-Lite; the PROTOCOL name "TCP" refers to both TCP and
MPTCP. We present "connection" as a general protocol-independent MPTCP. We present "connection" as a general protocol-independent
concept and use it to refer to, e.g., TCP connections (identifiable concept and use it to refer to, e.g., TCP connections (identifiable
by a unique pair of IP addresses and TCP port numbers), SCTP by a unique pair of IP addresses and TCP port numbers), SCTP
associations (identifiable by multiple IP address and port number associations (identifiable by multiple IP address and port number
pairs), as well UDP and UDP-Lite connections (identifiable by a pairs), as well UDP and UDP-Lite connections (identifiable by a
unique socket pair). unique socket pair).
Some minor details are omitted for the sake of generalization -- Some minor details are omitted for the sake of generalization --
e.g., SCTP's 'close' [RFC4960] returns success or failure, and lets e.g., SCTP's 'Close' [RFC4960] returns success or failure, and lets
the application control whether further receive or send operations or the application control whether further receive or send operations or
both are disabled [RFC6458]. This is not described in the same way both are disabled [RFC6458]. This is not described in the same way
for TCP [RFC0793], but these details play no significant role for the for TCP [RFC0793], but these details play no significant role for the
primitives provided by either TCP or SCTP (for the sake of being primitives provided by either TCP or SCTP (for the sake of being
generic, it could be assumed that both receive and send operations generic, it could be assumed that both receive and send operations
are disabled in both cases). are disabled in both cases).
The TCP 'send' and 'receive' primitives include usage of an "URGENT" The TCP 'Send' and 'Receive' primitives include usage of an 'urgent'
mechanism. This mechanism is required to implement the "synch parameter. This parameter controls a mechanism that is required to
signal" used by telnet [RFC0854], but SHOULD NOT be used by new implement the "synch signal" used by telnet [RFC0854], but SHOULD NOT
applications [RFC6093]. Because pass 2 is meant as a basis for the be used by new applications [RFC6093]. Because pass 2 is meant as a
creation of future systems, the "URGENT" mechanism is excluded. This basis for the creation of future systems, the "urgent" mechanism is
also concerns the notification "Urgent pointer advance" in the excluded. This also concerns the notification 'Urgent Pointer
ERROR_REPORT (section 4.2.4.1 of [RFC1122]). Advance' in the 'Error_Report' (section 4.2.4.1 of [RFC1122]).
Since LEDBAT is a congestion control mechanism and not a protocol, it Since LEDBAT is a congestion control mechanism and not a protocol, it
is not currently defined when to enable / disable or configure the is not currently defined when to enable / disable or configure the
mechanism. For instance, it could be a one-time choice upon mechanism. For instance, it could be a one-time choice upon
connection establishment or when listening for incoming connections, connection establishment or when listening for incoming connections,
in which case it should be categorized under CONNECTION.ESTABLISHMENT in which case it should be categorized under CONNECTION.ESTABLISHMENT
or CONNECTION.AVAILABILITY, respectively. To avoid unnecessarily or CONNECTION.AVAILABILITY, respectively. To avoid unnecessarily
limiting future implementations, it was decided to place it under limiting future implementations, it was decided to place it under
CONNECTION.MAINTENANCE, with all parameters that are described in the CONNECTION.MAINTENANCE, with all parameters that are described in the
specification [RFC6817] made configurable. specification [RFC6817] made configurable.
4.1. CONNECTION Related Primitives 4.1. CONNECTION Related Primitives
ESTABLISHMENT: ESTABLISHMENT:
Active creation of a connection from one transport endpoint to one or Active creation of a connection from one transport endpoint to one or
more transport endpoints. more transport endpoints.
Interfaces to UDP and UDP-Lite allow both connection-oriented and Interfaces to UDP and UDP-Lite allow both connection-oriented and
connection-less usage of the API [RFC8085]. connection-less usage of the API [RFC8085].
o CONNECT.TCP: o CONNECT.TCP:
Pass 1 primitive / event: 'open' (active) or 'open' (passive) with Pass 1 primitive / event: 'Open' (active) or 'Open' (passive) with
socket, followed by 'send' socket, followed by 'Send'
Parameters: 1 local IP address (optional); 1 destination transport Parameters: 1 local IP address (optional); 1 destination transport
address (for active open; else the socket and the local IP address address (for active open; else the socket and the local IP address
of the succeeding incoming connection request will be maintained); of the succeeding incoming connection request will be maintained);
timeout (optional); options (optional); MKT configuration timeout (optional); options (optional); MKT configuration
(optional); user message (optional) (optional); user message (optional)
Comments: If the local IP address is not provided, a default Comments: If the local IP address is not provided, a default
choice will automatically be made. The timeout can also be a choice will automatically be made. The timeout can also be a
retransmission count. The options are IP options to be used on retransmission count. The options are IP options to be used on
all segments of the connection. At least the Source Route option all segments of the connection. At least the Source Route option
is mandatory for TCP to provide. 'MKT configuration' refers to is mandatory for TCP to provide. 'MKT configuration' refers to
the ability to configure Master Key Tuples (MKTs) for the ability to configure Master Key Tuples (MKTs) for
authentication. The user message may be transmitted to the peer authentication. The user message may be transmitted to the peer
application immediately upon reception of the TCP SYN packet. To application immediately upon reception of the TCP SYN packet. To
benefit from the lower latency this provides as part of the benefit from the lower latency this provides as part of the
experimental TFO mechanism, its length must be at most the TCP's experimental TFO mechanism, its length must be at most the TCP's
maximum segment size (minus TCP options used in the SYN). The maximum segment size (minus TCP options used in the SYN). The
message may also be delivered more than once to the application on message may also be delivered more than once to the application on
the remote host. the remote host.
o CONNECT.SCTP: o CONNECT.SCTP:
Pass 1 primitive / event: 'initialize', followed by 'enable / Pass 1 primitive / event: 'Initialize', followed by 'Enable /
disable interleaving' (optional), followed by 'associate' Disable Interleaving' (optional), followed by 'Associate'
Parameters: list of local SCTP port number / IP address pairs Parameters: list of local SCTP port number / IP address pairs
(initialize); one or several sockets (identifying the peer); ('Initialize'); one or several sockets (identifying the peer);
outbound stream count; maximum allowed inbound stream count; outbound stream count; maximum allowed inbound stream count;
adaptation layer indication (optional); chunk types required to be adaptation layer indication (optional); chunk types required to be
authenticated (optional); request interleaving on/off; maximum authenticated (optional); request interleaving on/off; maximum
number of INIT attemps (optional); maximum init. RTO for INIT number of INIT attemps (optional); maximum init. RTO for INIT
(optional); user message (optional); remote UDP port number (optional); user message (optional); remote UDP port number
(optional) (optional)
Returns: socket list or failure Returns: socket list or failure
Comments: 'initialize' needs to be called only once per list of Comments: 'Initialize' needs to be called only once per list of
local SCTP port number / IP address pairs. One socket will local SCTP port number / IP address pairs. One socket will
automatically be chosen; it can later be changed in MAINTENANCE. automatically be chosen; it can later be changed in MAINTENANCE.
The user message may be transmitted to the peer application The user message may be transmitted to the peer application
immediately upon reception of the packet containing the COOKIE- immediately upon reception of the packet containing the COOKIE-
ECHO chunk. To benefit from the lower latency this provides, its ECHO chunk. To benefit from the lower latency this provides, its
length must be limited such that it fits into the packet length must be limited such that it fits into the packet
containing the COOKIE-ECHO chunk. If a remote UDP port number is containing the COOKIE-ECHO chunk. If a remote UDP port number is
provided, SCTP packets will be encapsulated in UDP. provided, SCTP packets will be encapsulated in UDP.
o CONNECT.MPTCP: o CONNECT.MPTCP:
This is similar to CONNECT.TCP except for one additional boolean This is similar to CONNECT.TCP except for one additional boolean
parameter that allows to enable or disable MPTCP for a particular parameter that allows to enable or disable MPTCP for a particular
connection or socket (default: enabled). connection or socket (default: enabled).
o CONNECT.UDP(-Lite): o CONNECT.UDP(-Lite):
Pass 1 primitive / event: 'connect' followed by 'send'. Pass 1 primitive / event: 'Connect' followed by 'Send'.
Parameters: 1 local IP address (default (ANY), or specified); 1 Parameters: 1 local IP address (default (ANY), or specified); 1
destination transport address; 1 local port (default (OS chooses), destination transport address; 1 local port (default (OS chooses),
or specified); 1 destination port (default (OS chooses), or or specified); 1 destination port (default (OS chooses), or
specified). specified).
Comments: Associates a transport address creating a UDP(-Lite) Comments: Associates a transport address creating a UDP(-Lite)
socket connection. This can be called again with a new transport socket connection. This can be called again with a new transport
address to create a new connection. The CONNECT function allows address to create a new connection. The CONNECT function allows
an application to receive errors from messages sent to a transport an application to receive errors from messages sent to a transport
address. address.
AVAILABILITY: AVAILABILITY:
Preparing to receive incoming connection requests. Preparing to receive incoming connection requests.
o LISTEN.TCP: o LISTEN.TCP:
Pass 1 primitive / event: 'open' (passive) Pass 1 primitive / event: 'Open' (passive)
Parameters: 1 local IP address (optional); 1 socket (optional); Parameters: 1 local IP address (optional); 1 socket (optional);
timeout (optional); buffer to receive a user message (optional); timeout (optional); buffer to receive a user message (optional);
MKT configuration (optional) MKT configuration (optional)
Comments: if the socket and/or local IP address is provided, this Comments: if the socket and/or local IP address is provided, this
waits for incoming connections from only and/or to only the waits for incoming connections from only and/or to only the
provided address. Else this waits for incoming connections provided address. Else this waits for incoming connections
without this / these constraint(s). ESTABLISHMENT can later be without this / these constraint(s). ESTABLISHMENT can later be
performed with 'send'. If a buffer is provided to receive a user performed with 'Send'. If a buffer is provided to receive a user
message, a user message can be received from a TFO-enabled sender message, a user message can be received from a TFO-enabled sender
before TCP's connection handshake is completed. This message may before TCP's connection handshake is completed. This message may
arrive multiple times. 'MKT configuration' refers to the ability arrive multiple times. 'MKT configuration' refers to the ability
to configure Master Key Tuples (MKTs) for authentication. to configure Master Key Tuples (MKTs) for authentication.
o LISTEN.SCTP: o LISTEN.SCTP:
Pass 1 primitive / event: 'initialize', followed by 'COMMUNICATION Pass 1 primitive / event: 'Initialize', followed by 'Communication
UP' or 'RESTART' notification and possibly 'ADAPTATION LAYER' Up' or 'Restart' notification and possibly 'Adaptation Layer'
notification notification
Parameters: list of local SCTP port number / IP address pairs Parameters: list of local SCTP port number / IP address pairs
(initialize) (initialize)
Returns: socket list; outbound stream count; inbound stream count; Returns: socket list; outbound stream count; inbound stream count;
adaptation layer indication; chunks required to be authenticated; adaptation layer indication; chunks required to be authenticated;
interleaving supported on both sides yes/no interleaving supported on both sides yes/no
Comments: initialize needs to be called only once per list of Comments: 'Initialize' needs to be called only once per list of
local SCTP port number / IP address pairs. COMMUNICATION UP can local SCTP port number / IP address pairs. 'Communication Up' can
also follow a COMMUNICATION LOST notification, indicating that the also follow a 'Communication Lost' notification, indicating that
lost communication is restored. If the peer has provided an the lost communication is restored. If the peer has provided an
adaptation layer indication, an 'ADAPTATION LAYER' notification is adaptation layer indication, an 'Adaptation Layer' notification is
issued. issued.
o LISTEN.MPTCP: o LISTEN.MPTCP:
This is similar to LISTEN.TCP except for one additional boolean This is similar to LISTEN.TCP except for one additional boolean
parameter that allows to enable or disable MPTCP for a particular parameter that allows to enable or disable MPTCP for a particular
connection or socket (default: enabled). connection or socket (default: enabled).
o LISTEN.UDP(-Lite): o LISTEN.UDP(-Lite):
Pass 1 primitive / event: 'receive'. Pass 1 primitive / event: 'Receive'.
Parameters: 1 local IP address (default (ANY), or specified); 1 Parameters: 1 local IP address (default (ANY), or specified); 1
destination transport address; local port (default (OS chooses), destination transport address; local port (default (OS chooses),
or specified); destination port (default (OS chooses), or or specified); destination port (default (OS chooses), or
specified). specified).
Comments: The receive function registers the application to listen Comments: The 'Receive' function registers the application to
for incoming UDP(-Lite) datagrams at an endpoint. listen for incoming UDP(-Lite) datagrams at an endpoint.
MAINTENANCE: MAINTENANCE:
Adjustments made to an open connection, or notifications about it. Adjustments made to an open connection, or notifications about it.
These are out-of-band messages to the protocol that can be issued at These are out-of-band messages to the protocol that can be issued at
any time, at least after a connection has been established and before any time, at least after a connection has been established and before
it has been terminated (with one exception: CHANGE_TIMEOUT.TCP can it has been terminated (with one exception: CHANGE_TIMEOUT.TCP can
only be issued for an open connection when DATA.SEND.TCP is called). only be issued for an open connection when DATA.SEND.TCP is called).
In some cases, these primitives can also be immediately issued during In some cases, these primitives can also be immediately issued during
ESTABLISHMENT or AVAILABILITY, without waiting for the connection to ESTABLISHMENT or AVAILABILITY, without waiting for the connection to
be opened (e.g. CHANGE_TIMEOUT.TCP can be done using TCP's 'open' be opened (e.g. CHANGE_TIMEOUT.TCP can be done using TCP's 'Open'
primitive). For UDP and UDP-Lite, these functions may establish a primitive). For UDP and UDP-Lite, these functions may establish a
setting per connection, but may also be changed per datagram message. setting per connection, but may also be changed per datagram message.
o CHANGE_TIMEOUT.TCP: o CHANGE_TIMEOUT.TCP:
Pass 1 primitive / event: 'open' or 'send' combined with Pass 1 primitive / event: 'Open' or 'Send' combined with
unspecified control of per-connection state variables unspecified control of per-connection state variables
Parameters: timeout value (optional); ADV_UTO (optional); boolean Parameters: timeout value (optional); adv_uto (optional); boolean
UTO_ENABLED (optional, default false); boolean CHANGEABLE uto_enabled (optional, default false); boolean changeable
(optional, default true) (optional, default true)
Comments: when sending data, an application can adjust the Comments: when sending data, an application can adjust the
connection's timeout value (time after which the connection will connection's timeout value (time after which the connection will
be aborted if data could not be delivered). If UTO_ENABLED is be aborted if data could not be delivered). If 'uto_enabled' is
true, the user timeout value (or, if provided, the value ADV_UTO) true, the 'timeout value' (or, if provided, the value 'adv_uto')
will be advertised for the TCP on the other side of the connection will be advertised for the TCP on the other side of the connection
to adapt its own user timeout accordingly. UTO_ENABLED controls to adapt its own user timeout accordingly. 'uto_enabled' controls
whether the UTO option is enabled for a connection. This applies whether the UTO option is enabled for a connection. This applies
to both sending and receiving. CHANGEABLE controls whether the to both sending and receiving. 'changeable' controls whether the
user timeout may be changed based on a UTO option received from user timeout may be changed based on a UTO option received from
the other end of the connection; it becomes false when 'timeout the other end of the connection; it becomes false when 'timeout
value' is used. value' is used.
o CHANGE_TIMEOUT.SCTP: o CHANGE_TIMEOUT.SCTP:
Pass 1 primitive / event: 'Change HeartBeat' combined with Pass 1 primitive / event: 'Change HeartBeat' combined with
'Configure Max. Retransmissions of an Association' 'Configure Max. Retransmissions of an Association'
Parameters: 'Change HeartBeat': heartbeat frequency; 'Configure Parameters: 'Change Heartbeat': heartbeat frequency; 'Configure
Max. Retransmissions of an Association': Association.Max.Retrans Max. Retransmissions of an Association': association.max.retrans
Comments: Change Heartbeat can enable / disable heartbeats in SCTP Comments: 'Change Heartbeat' can enable / disable heartbeats in
as well as change their frequency. The parameter SCTP as well as change their frequency. The parameter
Association.Max.Retrans defines after how many unsuccessful 'association.max.retrans' defines after how many unsuccessful
transmissions of any packets (including heartbeats) the transmissions of any packets (including heartbeats) the
association will be terminated; thus these two primitives / association will be terminated; thus these two primitives /
parameters together can yield a similar behavior for SCTP parameters together can yield a similar behavior for SCTP
associations as CHANGE_TIMEOUT.TCP does for TCP connections. associations as CHANGE_TIMEOUT.TCP does for TCP connections.
o DISABLE_NAGLE.TCP: o DISABLE_NAGLE.TCP:
Pass 1 primitive / event: not specified Pass 1 primitive / event: not specified
Parameters: one boolean value Parameters: one boolean value
Comments: the Nagle algorithm delays data transmission to increase Comments: the Nagle algorithm delays data transmission to increase
the chance to send a full-sized segment. An application must be the chance to send a full-sized segment. An application must be
able to disable this algorithm for a connection. able to disable this algorithm for a connection.
o DISABLE_NAGLE.SCTP: o DISABLE_NAGLE.SCTP:
Pass 1 primitive / event: 'Enable/disable NODELAY' Pass 1 primitive / event: 'Enable / Disable NoDelay'
Parameters: one boolean value Parameters: one boolean value
Comments: Nagle-like algorithms delay data transmission to Comments: Nagle-like algorithms delay data transmission to
increase the chance to send a full-sized packet. increase the chance to send a full-sized packet.
o REQUEST_HEARTBEAT.SCTP: o REQUEST_HEARTBEAT.SCTP:
Pass 1 primitive / event: 'Request HeartBeat' Pass 1 primitive / event: 'Request HeartBeat'
Parameters: socket Parameters: socket
Returns: success or failure Returns: success or failure
Comments: requests an immediate heartbeat on a path, returning Comments: requests an immediate heartbeat on a path, returning
success or failure. success or failure.
o ADD_PATH.MPTCP: o ADD_PATH.MPTCP:
Pass 1 primitive / event: not specified Pass 1 primitive / event: not specified
Parameters: local IP address and optionally the local port number Parameters: local IP address and optionally the local port number
Comments: the application specifies the local IP address and port Comments: the application specifies the local IP address and port
number that must be used for a new subflow. number that must be used for a new subflow.
o ADD_PATH.SCTP: o ADD_PATH.SCTP:
Pass 1 primitive / event: Change Local Address / Set Peer Primary Pass 1 primitive / event: 'Change Local Address / Set Peer
Primary'
Parameters: local IP address Parameters: local IP address
o REM_PATH.MPTCP: o REM_PATH.MPTCP:
Pass 1 primitive / event: not specified Pass 1 primitive / event: not specified
Parameters: local IP address, local port number, remote IP Parameters: local IP address; local port number; remote IP
address, remote port number address; remote port number
Comments: the application removes the subflow specified by the IP/ Comments: the application removes the subflow specified by the IP/
port-pair. The MPTCP implementation must trigger a removal of the port-pair. The MPTCP implementation must trigger a removal of the
subflow that belongs to this IP/port-pair. subflow that belongs to this IP/port-pair.
o REM_PATH.SCTP: o REM_PATH.SCTP:
Pass 1 primitive / event: 'Change Local Address / Set Peer Pass 1 primitive / event: 'Change Local Address / Set Peer
Primary' Primary'
Parameters: local IP address Parameters: local IP address
o SET_PRIMARY.SCTP: o SET_PRIMARY.SCTP:
skipping to change at page 26, line 34 skipping to change at page 25, line 34
o SET_PEER_PRIMARY.SCTP: o SET_PEER_PRIMARY.SCTP:
Pass 1 primitive / event: 'Change Local Address / Set Peer Pass 1 primitive / event: 'Change Local Address / Set Peer
Primary' Primary'
Parameters: local IP address Parameters: local IP address
Comments: this is only advisory for the peer. Comments: this is only advisory for the peer.
o CONFIG_SWITCHOVER.SCTP: o CONFIG_SWITCHOVER.SCTP:
Pass 1 primitive / event: 'Configure Path Switchover' Pass 1 primitive / event: 'Configure Path Switchover'
Parameters: primary max retrans (no. of retransmissions after Parameters: primary max retrans (no. of retransmissions after
which a path is considered inactive), PF max retrans (no. of which a path is considered inactive); PF max retrans (no. of
retransmissions after which a path is considered to be retransmissions after which a path is considered to be
"Potentially Failed", and others will be preferably used) "Potentially Failed", and others will be preferably used)
(optional) (optional)
o STATUS.SCTP: o STATUS.SCTP:
Pass 1 primitive / event: 'Status', 'Enable / Disable Pass 1 primitive / event: 'Status', 'Enable / Disable
Interleaving' and 'NETWORK STATUS CHANGE notification'. Interleaving' and 'Network Status Change' notification.
Returns: data block with information about a specified Returns: data block with information about a specified
association, containing: association connection state; destination association, containing: association connection state; destination
transport address list; destination transport address reachability transport address list; destination transport address reachability
states; current local and peer receiver window sizes; current states; current local and peer receiver window sizes; current
local congestion window sizes; number of unacknowledged DATA local congestion window sizes; number of unacknowledged DATA
chunks; number of DATA chunks pending receipt; primary path; most chunks; number of DATA chunks pending receipt; primary path; most
recent SRTT on primary path; RTO on primary path; SRTT and RTO on recent SRTT on primary path; RTO on primary path; SRTT and RTO on
other destination addresses; MTU per path; interleaving supported other destination addresses; MTU per path; interleaving supported
yes/no. yes/no.
Comments: The NETWORK STATUS CHANGE notification informs the Comments: The 'Network Status Change' notification informs the
application about a socket becoming active/inactive; this only application about a socket becoming active/inactive; this only
affects the programming style, as the same information is also affects the programming style, as the same information is also
available via 'Status'. available via 'Status'.
o STATUS.MPTCP: o STATUS.MPTCP:
Pass 1 primitive / event: not specified Pass 1 primitive / event: not specified
Returns: list of pairs of tuples of IP address and TCP port number Returns: list of pairs of tuples of IP address and TCP port number
of each subflow. The first of the pair is the local IP and port of each subflow. The first of the pair is the local IP and port
number, while the second is the remote IP and port number. number, while the second is the remote IP and port number.
skipping to change at page 27, line 38 skipping to change at page 26, line 26
Comments: this allows an application to change the DSCP value for Comments: this allows an application to change the DSCP value for
outgoing segments. outgoing segments.
o SET_DSCP.SCTP: o SET_DSCP.SCTP:
Pass 1 primitive / event: 'Set DSCP value' Pass 1 primitive / event: 'Set DSCP value'
Parameters: DSCP value Parameters: DSCP value
Comments: this allows an application to change the DSCP value for Comments: this allows an application to change the DSCP value for
outgoing packets on a path. outgoing packets on a path.
o SET_DSCP.UDP(-Lite): o SET_DSCP.UDP(-Lite):
Pass 1 primitive / event: 'SET_DSCP' Pass 1 primitive / event: 'Set_DSCP'
Parameter: DSCP value Parameter: DSCP value
Comments: This allows an application to change the DSCP value for Comments: This allows an application to change the DSCP value for
outgoing UDP(-Lite) datagrams. [RFC7657] and [RFC8085] provide outgoing UDP(-Lite) datagrams. [RFC7657] and [RFC8085] provide
current guidance on using this value with UDP. current guidance on using this value with UDP.
o ERROR.TCP: o ERROR.TCP:
Pass 1 primitive / event: 'ERROR_REPORT' Pass 1 primitive / event: 'Error_Report'
Returns: reason (encoding not specified); subreason (encoding not Returns: reason (encoding not specified); subreason (encoding not
specified) specified)
Comments: soft errors that can be ignored without harm by many Comments: soft errors that can be ignored without harm by many
applications; an application should be able to disable these applications; an application should be able to disable these
notifications. The reported conditions include at least: ICMP notifications. The reported conditions include at least: ICMP
error message arrived; Excessive Retransmissions. error message arrived; Excessive Retransmissions.
o ERROR.UDP(-Lite): o ERROR.UDP(-Lite):
Pass 1 primitive / event: 'ERROR_REPORT' Pass 1 primitive / event: 'Error_Report'
Returns: Error report Returns: Error report
Comments: This returns soft errors that may be ignored without Comments: This returns soft errors that may be ignored without
harm by many applications; An application must connect to be able harm by many applications; An application must connect to be able
receive these notifications. receive these notifications.
o SET_AUTH.TCP: o SET_AUTH.TCP:
Pass 1 primitive / event: not specified Pass 1 primitive / event: not specified
Parameters: current_key, rnext_key Parameters: current_key; rnext_key
Comments: current_key and rnext_key are the preferred outgoing MKT Comments: current_key and rnext_key are the preferred outgoing MKT
and the preferred incoming MKT, respectively, for a segment that and the preferred incoming MKT, respectively, for a segment that
is sent on the connection. is sent on the connection.
o SET_AUTH.SCTP: o SET_AUTH.SCTP:
Pass 1 primitive / event: 'Set / Get Authentication Parameters' Pass 1 primitive / event: 'Set / Get Authentication Parameters'
Parameters: key_id, key, hmac_id Parameters: key_id; key; hmac_id
o GET_AUTH.TCP: o GET_AUTH.TCP:
Pass 1 primitive / event: not specified Pass 1 primitive / event: not specified
Parameters: current_key, rnext_key Parameters: current_key; rnext_key
Comments: current_key and rnext_key are the preferred outgoing MKT Comments: current_key and rnext_key are the preferred outgoing MKT
and the preferred incoming MKT, respectively, that were carried on and the preferred incoming MKT, respectively, that were carried on
a recently received segment. a recently received segment.
o GET_AUTH.SCTP: o GET_AUTH.SCTP:
Pass 1 primitive / event: 'Set / Get Authentication Parameters' Pass 1 primitive / event: 'Set / Get Authentication Parameters'
Parameters: key_id, chunk_list Parameters: key_id; chunk_list
o RESET_STREAM.SCTP: o RESET_STREAM.SCTP:
Pass 1 primitive / event: 'Add / Reset Streams, Reset Association' Pass 1 primitive / event: 'Add / Reset Streams, Reset Association'
Parameters: sid, direction Parameters: sid; direction
o RESET_STREAM-EVENT.SCTP: o RESET_STREAM-EVENT.SCTP:
Pass 1 primitive / event: 'STREAM RESET notification' Pass 1 primitive / event: 'Stream Reset' notification
Parameters: information about the result of RESET_STREAM.SCTP. Parameters: information about the result of RESET_STREAM.SCTP.
Comments: This is issued when the procedure for resetting streams Comments: This is issued when the procedure for resetting streams
has completed. has completed.
o RESET_ASSOC.SCTP: o RESET_ASSOC.SCTP:
Pass 1 primitive / event: 'Add / Reset Streams, Reset Association' Pass 1 primitive / event: 'Add / Reset Streams, Reset Association'
Parameters: information related to the extension, defined in Parameters: information related to the extension, defined in
[RFC3260]. [RFC3260].
o RESET_ASSOC-EVENT.SCTP: o RESET_ASSOC-EVENT.SCTP:
Pass 1 primitive / event: 'ASSOCIATION RESET notification' Pass 1 primitive / event: 'Association Reset' notification
Parameters: information about the result of RESET_ASSOC.SCTP. Parameters: information about the result of RESET_ASSOC.SCTP.
Comments: This is issued when the procedure for resetting an Comments: this is issued when the procedure for resetting an
association has completed. association has completed.
o ADD_STREAM.SCTP: o ADD_STREAM.SCTP:
Pass 1 primitive / event: 'Add / Reset Streams, Reset Association' Pass 1 primitive / event: 'Add / Reset Streams, Reset Association'
Parameters: number if outgoing and incoming streams to be added Parameters: number if outgoing and incoming streams to be added
o ADD_STREAM-EVENT.SCTP: o ADD_STREAM-EVENT.SCTP:
Pass 1 primitive / event: 'STREAM CHANGE notification' Pass 1 primitive / event: 'Stream Change' notification
Parameters: information about the result of ADD_STREAM.SCTP. Parameters: information about the result of ADD_STREAM.SCTP.
Comments: This is issued when the procedure for adding a stream Comments: this is issued when the procedure for adding a stream
has completed. has completed.
o SET_STREAM_SCHEDULER.SCTP: o SET_STREAM_SCHEDULER.SCTP:
Pass 1 primitive / event: 'Set Stream Scheduler' Pass 1 primitive / event: 'Set Stream Scheduler'
Parameters: scheduler identifier Parameters: scheduler identifier
Comments: choice of First Come First Serve, Round Robin, Round Comments: choice of First Come First Serve, Round Robin, Round
Robin per Packet, Priority Based, Fair Bandwidth, Weighted Fair Robin per Packet, Priority Based, Fair Bandwidth, Weighted Fair
Queuing. Queuing.
o CONFIGURE_STREAM_SCHEDULER.SCTP: o CONFIGURE_STREAM_SCHEDULER.SCTP:
Pass 1 primitive / event: 'Configure Stream Scheduler' Pass 1 primitive / event: 'Configure Stream Scheduler'
Parameters: priority Parameters: priority
Comments: the priority value only applies when Priority Based or Comments: the priority value only applies when Priority Based or
Weighted Fair Queuing scheduling is chosen with Weighted Fair Queuing scheduling is chosen with
SET_STREAM_SCHEDULER.SCTP. The meaning of the parameter differs SET_STREAM_SCHEDULER.SCTP. The meaning of the parameter differs
between these two schedulers but in both cases it realizes some between these two schedulers but in both cases it realizes some
form of prioritization regarding how bandwidth is divided among form of prioritization regarding how bandwidth is divided among
streams. streams.
o SET_FLOWLABEL.SCTP: o SET_FLOWLABEL.SCTP:
Pass 1 primitive / event: 'Set IPv6 flow label' Pass 1 primitive / event: 'Set IPv6 Flow Label'
Parameters: flow label Parameters: flow label
Comments: this allows an application to change the IPv6 header's Comments: this allows an application to change the IPv6 header's
flow label field for outgoing packets on a path. flow label field for outgoing packets on a path.
o AUTHENTICATION_NOTIFICATION-EVENT.SCTP: o AUTHENTICATION_NOTIFICATION-EVENT.SCTP:
Pass 1 primitive / event: 'AUTHENTICATION notification' Pass 1 primitive / event: 'Authentication' notification
Returns: information regarding key management. Returns: information regarding key management.
o CONFIG_SEND_BUFFER.SCTP: o CONFIG_SEND_BUFFER.SCTP:
Pass 1 primitive / event: 'Configure send buffer size' Pass 1 primitive / event: 'Configure Send Buffer Size'
Parameters: size value in octets Parameters: size value in octets
o CONFIG_RECEIVE_BUFFER.SCTP: o CONFIG_RECEIVE_BUFFER.SCTP:
Pass 1 primitive / event: 'Configure receive buffer size' Pass 1 primitive / event: 'Configure Receive Buffer Size'
Parameters: size value in octets Parameters: size value in octets
Comments: this controls the receiver window. Comments: this controls the receiver window.
o CONFIG_FRAGMENTATION.SCTP: o CONFIG_FRAGMENTATION.SCTP:
Pass 1 primitive / event: 'Configure message fragmentation' Pass 1 primitive / event: 'Configure Message Fragmentation'
Parameters: one boolean value (enable/disable), maximum Parameters: one boolean value (enable/disable); maximum
fragmentation size (optional; default: PMTU) fragmentation size (optional; default: PMTU)
Comments: if fragmentation is enabled, messages exceeding the Comments: if fragmentation is enabled, messages exceeding the
maximum fragmentation size will be fragmented. If fragmentation maximum fragmentation size will be fragmented. If fragmentation
is disabled, trying to send a message that exceeds the maximum is disabled, trying to send a message that exceeds the maximum
fragmentation size will produce an error. fragmentation size will produce an error.
o CONFIG_PMTUD.SCTP: o CONFIG_PMTUD.SCTP:
Pass 1 primitive / event: 'Configure Path MTU Discovery' Pass 1 primitive / event: 'Configure Path MTU Discovery'
Parameters: one boolean value (PMTUD on/off), PMTU value Parameters: one boolean value (PMTUD on/off); PMTU value
(optional) (optional)
Returns: PMTU value Returns: PMTU value
Comments: This returns a meaningful PMTU value when PMTUD is Comments: this returns a meaningful PMTU value when PMTUD is
enabled (the boolean is true), and the PMTU value can be set if enabled (the boolean is true), and the PMTU value can be set if
PMTUD is disabled (the boolean is false) PMTUD is disabled (the boolean is false)
o CONFIG_DELAYED_SACK.SCTP: o CONFIG_DELAYED_SACK.SCTP:
Pass 1 primitive / event: 'Configure delayed SACK timer' Pass 1 primitive / event: 'Configure Delayed SACK Timer'
Parameters: one boolean value (delayed SACK on/off), timer value Parameters: one boolean value (delayed SACK on/off); timer value
(optional), number of packets to wait for (default 2) (optional); number of packets to wait for (default 2)
Comments: If delayed SACK is enabled, SCTP will send a SACK upon Comments: if delayed SACK is enabled, SCTP will send a SACK upon
either receiving the provided number of packets or when the timer either receiving the provided number of packets or when the timer
expires, whatever occurs first. expires, whatever occurs first.
o CONFIG_RTO.SCTP: o CONFIG_RTO.SCTP:
Pass 1 primitive / event: 'Configure RTO calculation' Pass 1 primitive / event: 'Configure RTO Calculation'
Parameters: init (optional), min (optional), max (optional) Parameters: init (optional); min (optional); max (optional)
Comments: This adjusts the initial, minimum and maximum RTO Comments: this adjusts the initial, minimum and maximum RTO
values. values.
o SET_COOKIE_LIFE.SCTP: o SET_COOKIE_LIFE.SCTP:
Pass 1 primitive / event: 'Set Cookie life value' Pass 1 primitive / event: 'Set Cookie Life Value'
Parameters: cookie life value Parameters: cookie life value
o SET_MAX_BURST.SCTP: o SET_MAX_BURST.SCTP:
Pass 1 primitive / event: 'Set maximum burst' Pass 1 primitive / event: 'Set Maximum Burst'
Parameters: max burst value Parameters: max burst value
Comments: not all implementations allow values above the default Comments: not all implementations allow values above the default
of 4. of 4.
o SET_PARTIAL_DELIVERY_POINT.SCTP: o SET_PARTIAL_DELIVERY_POINT.SCTP:
Pass 1 primitive / event: 'Set Partial Delivery Point' Pass 1 primitive / event: 'Set Partial Delivery Point'
Parameters: partial delivery point (integer) Parameters: partial delivery point (integer)
Comments: this parameter must be smaller or equal to the socket Comments: this parameter must be smaller or equal to the socket
receive buffer size. receive buffer size.
o SET_CHECKSUM_ENABLED.UDP: o SET_CHECKSUM_ENABLED.UDP:
Pass 1 primitive / event: 'CHECKSUM_ENABLED'. Pass 1 primitive / event: 'Checksum_Enabled'.
Parameters: 0 when zero checksum is used at sender, 1 for checksum Parameters: 0 when zero checksum is used at sender, 1 for checksum
at sender (default) at sender (default)
o SET_CHECKSUM_REQUIRED.UDP: o SET_CHECKSUM_REQUIRED.UDP:
Pass 1 primitive / event: 'REQUIRE_CHECKSUM'. Pass 1 primitive / event: 'Require_Checksum'.
Parameter: 0 to allow zero checksum, 1 when a non-zero checksum is Parameter: 0 to allow zero checksum, 1 when a non-zero checksum is
required (default) at receiver required (default) at receiver
o SET_CHECKSUM_COVERAGE.UDP-Lite: o SET_CHECKSUM_COVERAGE.UDP-Lite:
Pass 1 primitive / event: 'SET_CHECKSUM_COVERAGE' Pass 1 primitive / event: 'Set_Checksum_Coverage'
Parameters: Coverage length at sender (default maximum coverage) Parameters: coverage length at sender (default maximum coverage)
o SET_MIN_CHECKSUM_COVERAGE.UDP-Lite: o SET_MIN_CHECKSUM_COVERAGE.UDP-Lite:
Pass 1 primitive / event: 'SET_MIN_COVERAGE'. Pass 1 primitive / event: 'Set_Min_Coverage'.
Parameter: Coverage length at receiver (default minimum coverage) Parameter: coverage length at receiver (default minimum coverage)
o SET_DF.UDP(-Lite): o SET_DF.UDP(-Lite):
Pass 1 primitive event: 'SET_DF'. Pass 1 primitive event: 'Set_DF'.
Parameter: 0 when DF is not set (default) in the IPv4 header, 1 Parameter: 0 when DF is not set (default) in the IPv4 header, 1
when DF is set when DF is set
o GET_MMS_S.UDP(-Lite): o GET_MMS_S.UDP(-Lite):
Pass 1 primitive event: 'GET_MMS_S'. Pass 1 primitive event: 'Get_MM_S'.
Comments: this retrieves the maximum transport-message size that Comments: this retrieves the maximum transport-message size that
may be sent using a non-fragmented IP packet from the configured may be sent using a non-fragmented IP packet from the configured
interface. interface.
o GET_MMS_R.UDP(-Lite): o GET_MMS_R.UDP(-Lite):
Pass 1 primitive event: 'GET_MMS_R'. Pass 1 primitive event: 'Get_MMS_R'.
Comments: this retrieves the maximum transport-message size that Comments: this retrieves the maximum transport-message size that
may be received from the configured interface. may be received from the configured interface.
o SET_TTL.UDP(-Lite) (IPV6_UNICAST_HOPS): o SET_TTL.UDP(-Lite) (IPV6_UNICAST_HOPS):
Pass 1 primitive / event: 'SET_TTL' and 'SET_IPV6_UNICAST_HOPS' Pass 1 primitive / event: 'Set_TTL' and 'Set_IPV6_Unicast_Hops'
Parameters: IPv4 TTL value or IPv6 Hop Count value Parameters: IPv4 TTL value or IPv6 Hop Count value
Comments: This allows an application to change the IPv4 TTL of Comments: this allows an application to change the IPv4 TTL of
IPv6 Hop count value for outgoing UDP(-Lite) datagrams. IPv6 Hop count value for outgoing UDP(-Lite) datagrams.
o GET_TTL.UDP(-Lite) (IPV6_UNICAST_HOPS): o GET_TTL.UDP(-Lite) (IPV6_UNICAST_HOPS):
Pass 1 primitive / event: 'GET_TTL' and 'GET_IPV6_UNICAST_HOPS' Pass 1 primitive / event: 'Get_TTL' and 'Get_IPV6_Unicast_Hops'
Returns: IPv4 TTL value or IPv6 Hop Count value Returns: IPv4 TTL value or IPv6 Hop Count value
Comments: This allows an application to read the the IPv4 TTL of Comments: this allows an application to read the the IPv4 TTL of
IPv6 Hop count value from a received UDP(-Lite) datagram. IPv6 Hop count value from a received UDP(-Lite) datagram.
o SET_ECN.UDP(-Lite): o SET_ECN.UDP(-Lite):
Pass 1 primitive / event: 'SET_ECN' Pass 1 primitive / event: 'Set_ECN'
Parameters: ECN value Parameters: ECN value
Comments: This allows a UDP(-Lite) application to set the ECN Comments: this allows a UDP(-Lite) application to set the ECN
codepoint field for outgoing UDP(-Lite) datagrams. Defaults to codepoint field for outgoing UDP(-Lite) datagrams. Defaults to
sending '00'. sending '00'.
o GET_ECN.UDP(-Lite): o GET_ECN.UDP(-Lite):
Pass 1 primitive / event: 'GET_ECN' Pass 1 primitive / event: 'Get_ECN'
Parameters: ECN value Parameters: ECN value
Comments: This allows a UDP(-Lite) application to read the ECN Comments: this allows a UDP(-Lite) application to read the ECN
codepoint field from a received UDP(-Lite) datagram. codepoint field from a received UDP(-Lite) datagram.
o SET_IP_OPTIONS.UDP(-Lite): o SET_IP_OPTIONS.UDP(-Lite):
Pass 1 primitive / event: 'SET_IP_OPTIONS' Pass 1 primitive / event: 'Set_IP_Options'
Parameters: options Parameters: options
Comments: This allows a UDP(-Lite) application to set IP Options Comments: this allows a UDP(-Lite) application to set IP Options
for outgoing UDP(-Lite) datagrams. These options can at least be for outgoing UDP(-Lite) datagrams. These options can at least be
the Source Route, Record Route, and Time Stamp option. the Source Route, Record Route, and Time Stamp option.
o GET_IP_OPTIONS.UDP(-Lite): o GET_IP_OPTIONS.UDP(-Lite):
Pass 1 primitive / event: 'GET_IP_OPTIONS' Pass 1 primitive / event: 'Get_IP_Options'
Returns: options Returns: options
Comments: This allows a UDP(-Lite) application to receive any IP Comments: this allows a UDP(-Lite) application to receive any IP
options that are contained in a received UDP(-Lite) datagram. options that are contained in a received UDP(-Lite) datagram.
o CONFIGURE.LEDBAT: o CONFIGURE.LEDBAT:
Pass 1 primitive / event: N/A Pass 1 primitive / event: N/A
Parameters: enable (boolean), TARGET, ALLOWED_INCREASE, GAIN_INC, Parameters: enable (boolean); target; allowed_increase; gain_inc;
GAIN_DEC, BASE_HISTORY, CURRENT_FILTER, INIT_CWND, MIN_CWND gain_dec; base_history; current_filter; init_cwnd; min_cwnd
Comments: enable is a newly invented parameter that enables or Comments: 'enable' is a newly invented parameter that enables or
disables the whole LEDBAT service. disables the whole LEDBAT service.
TERMINATION: TERMINATION:
Gracefully or forcefully closing a connection, or being informed Gracefully or forcefully closing a connection, or being informed
about this event happening. about this event happening.
o CLOSE.TCP: o CLOSE.TCP:
Pass 1 primitive / event: 'close' Pass 1 primitive / event: 'Close'
Comments: this terminates the sending side of a connection after Comments: this terminates the sending side of a connection after
reliably delivering all remaining data. reliably delivering all remaining data.
o CLOSE.SCTP: o CLOSE.SCTP:
Pass 1 primitive / event: 'Shutdown' Pass 1 primitive / event: 'Shutdown'
Comments: this terminates a connection after reliably delivering Comments: this terminates a connection after reliably delivering
all remaining data. all remaining data.
o ABORT.TCP: o ABORT.TCP:
Pass 1 primitive / event: 'abort' Pass 1 primitive / event: 'Abort'
Comments: this terminates a connection without delivering Comments: this terminates a connection without delivering
remaining data and sends an error message to the other side. remaining data and sends an error message to the other side.
o ABORT.SCTP: o ABORT.SCTP:
Pass 1 primitive / event: 'abort' Pass 1 primitive / event: 'Abort'
Parameters: abort reason to be given to the peer (optional) Parameters: abort reason to be given to the peer (optional)
Comments: this terminates a connection without delivering Comments: this terminates a connection without delivering
remaining data and sends an error message to the other side. remaining data and sends an error message to the other side.
o ABORT.UDP(-Lite): o ABORT.UDP(-Lite):
Pass 1 primitive event: 'CLOSE' Pass 1 primitive event: 'Close'
Comments: this terminates a connection without delivering Comments: this terminates a connection without delivering
remaining data. No further UDP(-Lite) datagrams are sent/received remaining data. No further UDP(-Lite) datagrams are sent/received
for this transport service instance. for this transport service instance.
o TIMEOUT.TCP: o TIMEOUT.TCP:
Pass 1 primitive / event: 'USER TIMEOUT' event Pass 1 primitive / event: 'User Timeout' event
Comments: the application is informed that the connection is Comments: the application is informed that the connection is
aborted. This event is executed on expiration of the timeout set aborted. This event is executed on expiration of the timeout set
in CONNECTION.ESTABLISHMENT.CONNECT.TCP (possibly adjusted in in CONNECTION.ESTABLISHMENT.CONNECT.TCP (possibly adjusted in
CONNECTION.MAINTENANCE.CHANGE_TIMEOUT.TCP). CONNECTION.MAINTENANCE.CHANGE_TIMEOUT.TCP).
o TIMEOUT.SCTP: o TIMEOUT.SCTP:
Pass 1 primitive / event: 'COMMUNICATION LOST' event Pass 1 primitive / event: 'Communication Lost' event
Comments: the application is informed that the connection is Comments: the application is informed that the connection is
aborted. this event is executed on expiration of the timeout that aborted. this event is executed on expiration of the timeout that
should be enabled by default (see the beginning of section 8.3 in should be enabled by default (see the beginning of section 8.3 in
[RFC4960]) and was possibly adjusted in [RFC4960]) and was possibly adjusted in
CONNECTION.MAINTENANCE.CHANGE_TIMEOOUT.SCTP. CONNECTION.MAINTENANCE.CHANGE_TIMEOOUT.SCTP.
o ABORT-EVENT.TCP: o ABORT-EVENT.TCP:
Pass 1 primitive / event: not specified. Pass 1 primitive / event: not specified.
o ABORT-EVENT.SCTP: o ABORT-EVENT.SCTP:
Pass 1 primitive / event: 'COMMUNICATION LOST' event Pass 1 primitive / event: 'Communication Lost' event
Returns: abort reason from the peer (if available) Returns: abort reason from the peer (if available)
Comments: the application is informed that the other side has Comments: the application is informed that the other side has
aborted the connection using CONNECTION.TERMINATION.ABORT.SCTP. aborted the connection using CONNECTION.TERMINATION.ABORT.SCTP.
o CLOSE-EVENT.TCP: o CLOSE-EVENT.TCP:
Pass 1 primitive / event: not specified. Pass 1 primitive / event: not specified.
o CLOSE-EVENT.SCTP: o CLOSE-EVENT.SCTP:
Pass 1 primitive / event: 'SHUTDOWN COMPLETE' event Pass 1 primitive / event: 'Shutdown Complete' event
Comments: the application is informed that Comments: the application is informed that
CONNECTION.TERMINATION.CLOSE.SCTP was successfully completed. CONNECTION.TERMINATION.CLOSE.SCTP was successfully completed.
4.2. DATA Transfer Related Primitives 4.2. DATA Transfer Related Primitives
All primitives in this section refer to an existing connection, i.e. All primitives in this section refer to an existing connection, i.e.
a connection that was either established or made available for a connection that was either established or made available for
receiving data (although this is optional for the primitives of UDP(- receiving data (although this is optional for the primitives of UDP(-
Lite)). In addition to the listed parameters, all sending primitives Lite)). In addition to the listed parameters, all sending primitives
contain a reference to a data block and all receiving primitives contain a reference to a data block and all receiving primitives
contain a reference to available buffer space for the data. Note contain a reference to available buffer space for the data. Note
that CONNECT.TCP and LISTEN.TCP in the ESTABLISHMENT and AVAILABILITY that CONNECT.TCP and LISTEN.TCP in the ESTABLISHMENT and AVAILABILITY
category also allow to transfer data (an optional user message) category also allow to transfer data (an optional user message)
before the connection is fully established. before the connection is fully established.
o SEND.TCP: o SEND.TCP:
Pass 1 primitive / event: 'send' Pass 1 primitive / event: 'Send'
Parameters: timeout (optional), current_key (optional), rnext_key Parameters: timeout (optional); current_key (optional); rnext_key
(optional) (optional)
Comments: this gives TCP a data block for reliable transmission to Comments: this gives TCP a data block for reliable transmission to
the TCP on the other side of the connection. The timeout can be the TCP on the other side of the connection. The timeout can be
configured with this call (see also configured with this call (see also
CONNECTION.MAINTENANCE.CHANGE_TIMEOUT.TCP). current_key and CONNECTION.MAINTENANCE.CHANGE_TIMEOUT.TCP). 'current_key' and
rnext_key are authentication parameters that can be configured 'rnext_key' are authentication parameters that can be configured
with this call (see also CONNECTION.MAINTENANCE.SET_AUTH.TCP). with this call (see also CONNECTION.MAINTENANCE.SET_AUTH.TCP).
o SEND.SCTP: o SEND.SCTP:
Pass 1 primitive / event: 'Send' Pass 1 primitive / event: 'Send'
Parameters: stream number; context (optional); socket (optional); Parameters: stream number; context (optional); socket (optional);
unordered flag (optional); no-bundle flag (optional); payload unordered flag (optional); no-bundle flag (optional); payload
protocol-id (optional); pr-policy (optional) pr-value (optional); protocol-id (optional); pr-policy (optional) pr-value (optional);
sack-immediately flag (optional); key-id (optional) sack-immediately flag (optional); key-id (optional)
Comments: this gives SCTP a data block for transmission to the Comments: this gives SCTP a data block for transmission to the
SCTP on the other side of the connection (SCTP association). The SCTP on the other side of the connection (SCTP association). The
skipping to change at page 37, line 13 skipping to change at page 33, line 42
'no-bundle flag' can be set to indicate a preference to avoid 'no-bundle flag' can be set to indicate a preference to avoid
bundling. The 'payload protocol-id' is a number that will, if bundling. The 'payload protocol-id' is a number that will, if
provided, be handed over to the receiving application. Using pr- provided, be handed over to the receiving application. Using pr-
policy and pr-value the level of reliability can be controlled. policy and pr-value the level of reliability can be controlled.
The 'sack-immediately' flag can be used to indicate that the peer The 'sack-immediately' flag can be used to indicate that the peer
should not delay the sending of a SACK corresponding to the should not delay the sending of a SACK corresponding to the
provided user message. If specified, the provided key-id is used provided user message. If specified, the provided key-id is used
for authenticating the user message. for authenticating the user message.
o SEND.UDP(-Lite): o SEND.UDP(-Lite):
Pass 1 primitive / event: 'SEND' Pass 1 primitive / event: 'Send'
Parameters: IP Address and Port Number of the destination endpoint Parameters: IP Address and Port Number of the destination endpoint
(optional if connected). (optional if connected)
Comments: This provides a message for unreliable transmission Comments: this provides a message for unreliable transmission
using UDP(-Lite) to the specified transport address. IP address using UDP(-Lite) to the specified transport address. IP address
and Port may be omitted for connected UDP(-Lite) sockets. All and Port may be omitted for connected UDP(-Lite) sockets. All
CONNECTION.MAINTENANCE.SET_*.UDP(-Lite) primitives apply per CONNECTION.MAINTENANCE.SET_*.UDP(-Lite) primitives apply per
message sent. message sent.
o RECEIVE.TCP: o RECEIVE.TCP:
Pass 1 primitive / event: 'receive'. Pass 1 primitive / event: 'Receive'.
Parameters: current_key (optional), rnext_key (optional). Parameters: current_key (optional); rnext_key (optional)
Comments: current_key and rnext_key are authentication parameters Comments: 'current_key' and 'rnext_key' are authentication
that can be read with this call (see also parameters that can be read with this call (see also
CONNECTION.MAINTENANCE.GET_AUTH.TCP). CONNECTION.MAINTENANCE.GET_AUTH.TCP).
o RECEIVE.SCTP: o RECEIVE.SCTP:
Pass 1 primitive / event: 'DATA ARRIVE' notification, followed by Pass 1 primitive / event: 'Data Arrive' notification, followed by
'Receive' 'Receive'
Parameters: stream number (optional) Parameters: stream number (optional)
Returns: stream sequence number (optional), partial flag Returns: stream sequence number (optional); partial flag
(optional) (optional)
Comments: if the 'stream number' is provided, the call to receive Comments: if the 'stream number' is provided, the call to receive
only receives data on one particular stream. If a partial message only receives data on one particular stream. If a partial message
arrives, this is indicated by the 'partial flag', and then the arrives, this is indicated by the 'partial flag', and then the
'stream sequence number' must be provided such that an application 'stream sequence number' must be provided such that an application
can restore the correct order of data blocks that comprise an can restore the correct order of data blocks that comprise an
entire message. Additionally, a delivery number lets the entire message. Additionally, a delivery number lets the
application detect reordering. application detect reordering.
o RECEIVE.UDP(-Lite): o RECEIVE.UDP(-Lite):
Pass 1 primitive / event: 'Receive',
Pass 1 primitive / event: 'RECEIVE', Parameters: buffer for received datagram
Parameters: Buffer for received datagram. Comments: all CONNECTION.MAINTENANCE.GET_*.UDP(-Lite) primitives
Comments: All CONNECTION.MAINTENANCE.GET_*.UDP(-Lite) primitives
apply per message received. apply per message received.
o SENDFAILURE-EVENT.SCTP: o SENDFAILURE-EVENT.SCTP:
Pass 1 primitive / event: 'SEND FAILURE' notification, optionally Pass 1 primitive / event: 'Send Failure' notification, optionally
followed by 'Receive Unsent Message' or 'Receive Unacknowledged followed by 'Receive Unsent Message' or 'Receive Unacknowledged
Message' Message'
Returns: cause code; context; unsent or unacknowledged message Returns: cause code; context; unsent or unacknowledged message
(optional) (optional)
Comments: 'cause code' indicates the reason of the failure, and Comments: 'cause code' indicates the reason of the failure, and
'context' is the context number if such a number has been provided 'context' is the context number if such a number has been provided
in DATA.SEND.SCTP, for later use with 'Receive Unsent Message' or in DATA.SEND.SCTP, for later use with 'Receive Unsent Message' or
'Receive Unacknowledged Message', respectively. These primitives 'Receive Unacknowledged Message', respectively. These primitives
can be used to retrieve the unsent or unacknowledged message (or can be used to retrieve the unsent or unacknowledged message (or
part of the message, in case a part was delivered) if desired. part of the message, in case a part was delivered) if desired.
o SEND_FAILURE.UDP(-Lite): o SEND_FAILURE.UDP(-Lite):
Pass 1 primitive / event: 'SEND' Pass 1 primitive / event: 'Send'
Comments: This may be used to probe for the effective PMTU when Comments: this may be used to probe for the effective PMTU when
using in combination with the 'MAINTENANCE.SET_DF' primitive. using in combination with the 'MAINTENANCE.SET_DF' primitive.
o SENDER_DRY-EVENT.SCTP: o SENDER_DRY-EVENT.SCTP:
Pass 1 primitive / event: 'SENDER DRY' notification Pass 1 primitive / event: 'Sender Dry' notification
Comments: This informs the application that the stack has no more Comments: this informs the application that the stack has no more
user data to send. user data to send.
o PARTIAL_DELIVERY_ABORTED-EVENT.SCTP: o PARTIAL_DELIVERY_ABORTED-EVENT.SCTP:
Pass 1 primitive / event: 'PARTIAL DELIVERY ABORTED' notification Pass 1 primitive / event: 'Partial Delivery Aborted' notification
Comments: This informs the receiver of a partial message that the Comments: this informs the receiver of a partial message that the
further delivery of the message has been aborted. further delivery of the message has been aborted.
5. Pass 3 5. Pass 3
This section presents the superset of all transport features in all This section presents the superset of all transport features in all
protocols that were discussed in the preceding sections, based on the protocols that were discussed in the preceding sections, based on the
list of primitives in pass 2 but also on text in pass 1 to include list of primitives in pass 2 but also on text in pass 1 to include
transport features that can be configured in one protocol and are transport features that can be configured in one protocol and are
static properties in another (congestion control, for example). static properties in another (congestion control, for example).
Again, some minor details are omitted for the sake of generalization Again, some minor details are omitted for the sake of generalization
-- e.g., TCP may provide various different IP options, but only -- e.g., TCP may provide various different IP options, but only
source route is mandatory to implement, and this detail is not source route is mandatory to implement, and this detail is not
visible in the Pass 3 transport feature "Specify IP Options". visible in the Pass 3 transport feature "Specify IP Options". As
before, "UDP(-Lite)" represents both UDP and UDP-Lite, and TCP refers
to both TCP and MPTCP.
5.1. CONNECTION Related Transport Features 5.1. CONNECTION Related Transport Features
ESTABLISHMENT: ESTABLISHMENT:
Active creation of a connection from one transport endpoint to one or Active creation of a connection from one transport endpoint to one or
more transport endpoints. more transport endpoints.
o Connect o Connect
Protocols: TCP, SCTP, UDP(-Lite) Protocols: TCP, SCTP, UDP(-Lite)
skipping to change at page 40, line 10 skipping to change at page 36, line 10
Protocols: TCP, SCTP Protocols: TCP, SCTP
o Obtain multiple sockets o Obtain multiple sockets
Protocols: SCTP Protocols: SCTP
o Disable MPTCP o Disable MPTCP
Protocols: MPTCP Protocols: MPTCP
o Configure authentication o Configure authentication
Protocols: TCP, SCTP Protocols: TCP, SCTP
Comments: With TCP, this allows to configure Master Key Tuples Comments: with TCP, this allows to configure Master Key Tuples
(MKTs). In SCTP, this allows to specify which chunk types must (MKTs). In SCTP, this allows to specify which chunk types must
always be authenticated. DATA, ACK etc. are different 'chunks' in always be authenticated. DATA, ACK etc. are different 'chunks' in
SCTP; one or more chunks may be included in a single packet. SCTP; one or more chunks may be included in a single packet.
o Indicate an Adaptation Layer (via an adaptation code point) o Indicate an Adaptation Layer (via an adaptation code point)
Protocols: SCTP Protocols: SCTP
o Request to negotiate interleaving of user messages o Request to negotiate interleaving of user messages
Protocols: SCTP Protocols: SCTP
skipping to change at page 41, line 25 skipping to change at page 37, line 10
Protocols: SCTP Protocols: SCTP
o Specify which IP Options must always be used o Specify which IP Options must always be used
Protocols: TCP, UDP(-Lite) Protocols: TCP, UDP(-Lite)
o Disable MPTCP o Disable MPTCP
Protocols: MPTCP Protocols: MPTCP
o Configure authentication o Configure authentication
Protocols: TCP, SCTP Protocols: TCP, SCTP
Comments: With TCP, this allows to configure Master Key Tuples Comments: with TCP, this allows to configure Master Key Tuples
(MKTs). In SCTP, this allows to specify which chunk types must (MKTs). In SCTP, this allows to specify which chunk types must
always be authenticated. DATA, ACK etc. are different 'chunks' in always be authenticated. DATA, ACK etc. are different 'chunks' in
SCTP; one or more chunks may be included in a single packet. SCTP; one or more chunks may be included in a single packet.
o Indicate an Adaptation Layer (via an adaptation code point) o Indicate an Adaptation Layer (via an adaptation code point)
Protocols: SCTP Protocols: SCTP
MAINTENANCE: MAINTENANCE:
Adjustments made to an open connection, or notifications about it. Adjustments made to an open connection, or notifications about it.
skipping to change at page 47, line 14 skipping to change at page 40, line 48
Protocols: A protocol implementing the LEDBAT congestion control Protocols: A protocol implementing the LEDBAT congestion control
mechanism mechanism
TERMINATION: TERMINATION:
Gracefully or forcefully closing a connection, or being informed Gracefully or forcefully closing a connection, or being informed
about this event happening. about this event happening.
o Close after reliably delivering all remaining data, causing an o Close after reliably delivering all remaining data, causing an
event informing the application on the other side event informing the application on the other side
Protocols: TCP, SCTP Protocols: TCP, SCTP
Comments: A TCP endpoint locally only closes the connection for Comments: a TCP endpoint locally only closes the connection for
sending; it may still receive data afterwards. sending; it may still receive data afterwards.
o Abort without delivering remaining data, causing an event o Abort without delivering remaining data, causing an event
informing the application on the other side informing the application on the other side
Protocols: TCP, SCTP Protocols: TCP, SCTP
Comments: In SCTP a reason can optionally be given by the Comments: in SCTP a reason can optionally be given by the
application on the aborting side, which can then be received by application on the aborting side, which can then be received by
the application on the other side. the application on the other side.
o Abort without delivering remaining data, not causing an event o Abort without delivering remaining data, not causing an event
informing the application on the other side informing the application on the other side
Protocols: UDP(-Lite) Protocols: UDP(-Lite)
o Timeout event when data could not be delivered for too long o Timeout event when data could not be delivered for too long
Protocols: TCP, SCTP Protocols: TCP, SCTP
Comments: the timeout is configured with CONNECTION.MAINTENANCE Comments: the timeout is configured with CONNECTION.MAINTENANCE
skipping to change at page 50, line 7 skipping to change at page 42, line 50
Protocols: TCP Protocols: TCP
o Receive a message o Receive a message
Protocols: SCTP, UDP(-Lite) Protocols: SCTP, UDP(-Lite)
o Choice of stream to receive from o Choice of stream to receive from
Protocols: SCTP Protocols: SCTP
o Information about partial message arrival o Information about partial message arrival
Protocols: SCTP Protocols: SCTP
Comments: In SCTP, partial messages are combined with a stream Comments: in SCTP, partial messages are combined with a stream
sequence number so that the application can restore the correct sequence number so that the application can restore the correct
order of data blocks an entire message consists of. order of data blocks an entire message consists of.
o Obtain a message delivery number o Obtain a message delivery number
Protocols: SCTP Protocols: SCTP
Comments: This number can let applications detect and, if desired, Comments: this number can let applications detect and, if desired,
correct reordering. correct reordering.
5.2.3. Errors 5.2.3. Errors
This section describes sending failures that are associated with a This section describes sending failures that are associated with a
specific call to DATA.SEND from pass 2. specific call to DATA.SEND from pass 2.
o Notification of an unsent (part of a) message o Notification of an unsent (part of a) message
Protocols: SCTP, UDP(-Lite) Protocols: SCTP, UDP(-Lite)
skipping to change at page 50, line 37 skipping to change at page 43, line 32
o Notification that the stack has no more user data to send o Notification that the stack has no more user data to send
Protocols: SCTP Protocols: SCTP
o Notification to a receiver that a partial message delivery has o Notification to a receiver that a partial message delivery has
been aborted been aborted
Protocols: SCTP Protocols: SCTP
6. Acknowledgements 6. Acknowledgements
The authors would like to thank (in alphabetical order) Bob Briscoe, The authors would like to thank (in alphabetical order) Bob Briscoe,
David Hayes, Karen Nielsen, Joe Touch and Brian Trammell for Aaron Falk, David Hayes, Karen Nielsen, Tommy Pauly, Joe Touch and
providing valuable feedback on this document. We especially thank Brian Trammell for providing valuable feedback on this document. We
Christoph Paasch for providing input related to Multipath TCP, and especially thank Christoph Paasch for providing input related to
Gorry Fairhurst and Tom Jones for providing input related to UDP(- Multipath TCP, and Gorry Fairhurst and Tom Jones for providing input
Lite). This work has received funding from the European Union's related to UDP(-Lite). This work has received funding from the
Horizon 2020 research and innovation programme under grant agreement European Union's Horizon 2020 research and innovation programme under
No. 644334 (NEAT). The views expressed are solely those of the grant agreement No. 644334 (NEAT). The views expressed are solely
author(s). those of the author(s).
7. IANA Considerations 7. IANA Considerations
XX RFC ED - PLEASE REMOVE THIS SECTION XXX XX RFC ED - PLEASE REMOVE THIS SECTION XXX
This memo includes no request to IANA. This memo includes no request to IANA.
8. Security Considerations 8. Security Considerations
Authentication, confidentiality protection, and integrity protection Authentication, confidentiality protection, and integrity protection
skipping to change at page 51, line 39 skipping to change at page 44, line 27
Security considerations for the use of UDP and UDP-Lite are provided Security considerations for the use of UDP and UDP-Lite are provided
in the referenced RFCs. Security guidance for application usage is in the referenced RFCs. Security guidance for application usage is
provided in the UDP-Guidelines [RFC8085]. provided in the UDP-Guidelines [RFC8085].
9. References 9. References
9.1. Normative References 9.1. Normative References
[FJ16] Fairhurst, G. and T. Jones, "Features of the User Datagram [FJ16] Fairhurst, G. and T. Jones, "Features of the User Datagram
Protocol (UDP) and Lightweight UDP (UDP-Lite) Transport Protocol (UDP) and Lightweight UDP (UDP-Lite) Transport
Protocols", Internet-draft draft-ietf-taps-transports- Protocols", draft-ietf-taps-transports-usage-udp-02 (work
usage-udp-02, May 2017. in progress), May 2017.
[I-D.ietf-tsvwg-sctp-ndata] [I-D.ietf-tsvwg-sctp-ndata]
Stewart, R., Tuexen, M., Loreto, S., and R. Seggelmann, Stewart, R., Tuexen, M., Loreto, S., and R. Seggelmann,
"Stream Schedulers and User Message Interleaving for the "Stream Schedulers and User Message Interleaving for the
Stream Control Transmission Protocol", draft-ietf-tsvwg- Stream Control Transmission Protocol",
sctp-ndata-08 (work in progress), October 2016. draft-ietf-tsvwg-sctp-ndata-08 (work in progress),
October 2016.
[RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, [RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768,
DOI 10.17487/RFC0768, August 1980, DOI 10.17487/RFC0768, August 1980,
<http://www.rfc-editor.org/info/rfc768>. <http://www.rfc-editor.org/info/rfc768>.
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7, [RFC0793] Postel, J., "Transmission Control Protocol", STD 7,
RFC 793, DOI 10.17487/RFC0793, September 1981, RFC 793, DOI 10.17487/RFC0793, September 1981,
<http://www.rfc-editor.org/info/rfc793>. <http://www.rfc-editor.org/info/rfc793>.
[RFC1122] Braden, R., Ed., "Requirements for Internet Hosts - [RFC1122] Braden, R., Ed., "Requirements for Internet Hosts -
Communication Layers", STD 3, RFC 1122, Communication Layers", STD 3, RFC 1122, DOI 10.17487/
DOI 10.17487/RFC1122, October 1989, RFC1122, October 1989,
<http://www.rfc-editor.org/info/rfc1122>. <http://www.rfc-editor.org/info/rfc1122>.
[RFC3758] Stewart, R., Ramalho, M., Xie, Q., Tuexen, M., and P. [RFC3758] Stewart, R., Ramalho, M., Xie, Q., Tuexen, M., and P.
Conrad, "Stream Control Transmission Protocol (SCTP) Conrad, "Stream Control Transmission Protocol (SCTP)
Partial Reliability Extension", RFC 3758, Partial Reliability Extension", RFC 3758, DOI 10.17487/
DOI 10.17487/RFC3758, May 2004, RFC3758, May 2004,
<http://www.rfc-editor.org/info/rfc3758>. <http://www.rfc-editor.org/info/rfc3758>.
[RFC4895] Tuexen, M., Stewart, R., Lei, P., and E. Rescorla, [RFC4895] Tuexen, M., Stewart, R., Lei, P., and E. Rescorla,
"Authenticated Chunks for the Stream Control Transmission "Authenticated Chunks for the Stream Control Transmission
Protocol (SCTP)", RFC 4895, DOI 10.17487/RFC4895, August Protocol (SCTP)", RFC 4895, DOI 10.17487/RFC4895,
2007, <http://www.rfc-editor.org/info/rfc4895>. August 2007, <http://www.rfc-editor.org/info/rfc4895>.
[RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol", [RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol",
RFC 4960, DOI 10.17487/RFC4960, September 2007, RFC 4960, DOI 10.17487/RFC4960, September 2007,
<http://www.rfc-editor.org/info/rfc4960>. <http://www.rfc-editor.org/info/rfc4960>.
[RFC5061] Stewart, R., Xie, Q., Tuexen, M., Maruyama, S., and M. [RFC5061] Stewart, R., Xie, Q., Tuexen, M., Maruyama, S., and M.
Kozuka, "Stream Control Transmission Protocol (SCTP) Kozuka, "Stream Control Transmission Protocol (SCTP)
Dynamic Address Reconfiguration", RFC 5061, Dynamic Address Reconfiguration", RFC 5061, DOI 10.17487/
DOI 10.17487/RFC5061, September 2007, RFC5061, September 2007,
<http://www.rfc-editor.org/info/rfc5061>. <http://www.rfc-editor.org/info/rfc5061>.
[RFC5482] Eggert, L. and F. Gont, "TCP User Timeout Option", [RFC5482] Eggert, L. and F. Gont, "TCP User Timeout Option",
RFC 5482, DOI 10.17487/RFC5482, March 2009, RFC 5482, DOI 10.17487/RFC5482, March 2009,
<http://www.rfc-editor.org/info/rfc5482>. <http://www.rfc-editor.org/info/rfc5482>.
[RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP [RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP
Authentication Option", RFC 5925, DOI 10.17487/RFC5925, Authentication Option", RFC 5925, DOI 10.17487/RFC5925,
June 2010, <http://www.rfc-editor.org/info/rfc5925>. June 2010, <http://www.rfc-editor.org/info/rfc5925>.
[RFC6182] Ford, A., Raiciu, C., Handley, M., Barre, S., and J. [RFC6182] Ford, A., Raiciu, C., Handley, M., Barre, S., and J.
Iyengar, "Architectural Guidelines for Multipath TCP Iyengar, "Architectural Guidelines for Multipath TCP
Development", RFC 6182, DOI 10.17487/RFC6182, March 2011, Development", RFC 6182, DOI 10.17487/RFC6182, March 2011,
<http://www.rfc-editor.org/info/rfc6182>. <http://www.rfc-editor.org/info/rfc6182>.
[RFC6458] Stewart, R., Tuexen, M., Poon, K., Lei, P., and V. [RFC6458] Stewart, R., Tuexen, M., Poon, K., Lei, P., and V.
Yasevich, "Sockets API Extensions for the Stream Control Yasevich, "Sockets API Extensions for the Stream Control
Transmission Protocol (SCTP)", RFC 6458, Transmission Protocol (SCTP)", RFC 6458, DOI 10.17487/
DOI 10.17487/RFC6458, December 2011, RFC6458, December 2011,
<http://www.rfc-editor.org/info/rfc6458>. <http://www.rfc-editor.org/info/rfc6458>.
[RFC6525] Stewart, R., Tuexen, M., and P. Lei, "Stream Control [RFC6525] Stewart, R., Tuexen, M., and P. Lei, "Stream Control
Transmission Protocol (SCTP) Stream Reconfiguration", Transmission Protocol (SCTP) Stream Reconfiguration",
RFC 6525, DOI 10.17487/RFC6525, February 2012, RFC 6525, DOI 10.17487/RFC6525, February 2012,
<http://www.rfc-editor.org/info/rfc6525>. <http://www.rfc-editor.org/info/rfc6525>.
[RFC6817] Shalunov, S., Hazel, G., Iyengar, J., and M. Kuehlewind, [RFC6817] Shalunov, S., Hazel, G., Iyengar, J., and M. Kuehlewind,
"Low Extra Delay Background Transport (LEDBAT)", RFC 6817, "Low Extra Delay Background Transport (LEDBAT)", RFC 6817,
DOI 10.17487/RFC6817, December 2012, DOI 10.17487/RFC6817, December 2012,
skipping to change at page 53, line 26 skipping to change at page 46, line 16
"TCP Extensions for Multipath Operation with Multiple "TCP Extensions for Multipath Operation with Multiple
Addresses", RFC 6824, DOI 10.17487/RFC6824, January 2013, Addresses", RFC 6824, DOI 10.17487/RFC6824, January 2013,
<http://www.rfc-editor.org/info/rfc6824>. <http://www.rfc-editor.org/info/rfc6824>.
[RFC6897] Scharf, M. and A. Ford, "Multipath TCP (MPTCP) Application [RFC6897] Scharf, M. and A. Ford, "Multipath TCP (MPTCP) Application
Interface Considerations", RFC 6897, DOI 10.17487/RFC6897, Interface Considerations", RFC 6897, DOI 10.17487/RFC6897,
March 2013, <http://www.rfc-editor.org/info/rfc6897>. March 2013, <http://www.rfc-editor.org/info/rfc6897>.
[RFC6951] Tuexen, M. and R. Stewart, "UDP Encapsulation of Stream [RFC6951] Tuexen, M. and R. Stewart, "UDP Encapsulation of Stream
Control Transmission Protocol (SCTP) Packets for End-Host Control Transmission Protocol (SCTP) Packets for End-Host
to End-Host Communication", RFC 6951, to End-Host Communication", RFC 6951, DOI 10.17487/
DOI 10.17487/RFC6951, May 2013, RFC6951, May 2013,
<http://www.rfc-editor.org/info/rfc6951>. <http://www.rfc-editor.org/info/rfc6951>.
[RFC7053] Tuexen, M., Ruengeler, I., and R. Stewart, "SACK- [RFC7053] Tuexen, M., Ruengeler, I., and R. Stewart, "SACK-
IMMEDIATELY Extension for the Stream Control Transmission IMMEDIATELY Extension for the Stream Control Transmission
Protocol", RFC 7053, DOI 10.17487/RFC7053, November 2013, Protocol", RFC 7053, DOI 10.17487/RFC7053, November 2013,
<http://www.rfc-editor.org/info/rfc7053>. <http://www.rfc-editor.org/info/rfc7053>.
[RFC7413] Cheng, Y., Chu, J., Radhakrishnan, S., and A. Jain, "TCP [RFC7413] Cheng, Y., Chu, J., Radhakrishnan, S., and A. Jain, "TCP
Fast Open", RFC 7413, DOI 10.17487/RFC7413, December 2014, Fast Open", RFC 7413, DOI 10.17487/RFC7413, December 2014,
<http://www.rfc-editor.org/info/rfc7413>. <http://www.rfc-editor.org/info/rfc7413>.
skipping to change at page 54, line 13 skipping to change at page 46, line 49
<http://www.rfc-editor.org/info/rfc7829>. <http://www.rfc-editor.org/info/rfc7829>.
[RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage [RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage
Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085, Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085,
March 2017, <http://www.rfc-editor.org/info/rfc8085>. March 2017, <http://www.rfc-editor.org/info/rfc8085>.
9.2. Informative References 9.2. Informative References
[I-D.draft-gjessing-taps-minset] [I-D.draft-gjessing-taps-minset]
Gjessing, S. and M. Welzl, "A Minimal Set of Transport Gjessing, S. and M. Welzl, "A Minimal Set of Transport
Services for TAPS Systems", Internet-draft draft-gjessing- Services for TAPS Systems", draft-gjessing-taps-minset-05
taps-minset-04, March 2017. (work in progress), June 2017.
[RFC0854] Postel, J. and J. Reynolds, "Telnet Protocol [RFC0854] Postel, J. and J. Reynolds, "Telnet Protocol
Specification", STD 8, RFC 854, DOI 10.17487/RFC0854, May Specification", STD 8, RFC 854, DOI 10.17487/RFC0854,
1983, <http://www.rfc-editor.org/info/rfc854>. May 1983, <http://www.rfc-editor.org/info/rfc854>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/
DOI 10.17487/RFC2119, March 1997, RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, [RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS "Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474, Field) in the IPv4 and IPv6 Headers", RFC 2474,
DOI 10.17487/RFC2474, December 1998, DOI 10.17487/RFC2474, December 1998,
<http://www.rfc-editor.org/info/rfc2474>. <http://www.rfc-editor.org/info/rfc2474>.
[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z., [RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
and W. Weiss, "An Architecture for Differentiated and W. Weiss, "An Architecture for Differentiated
skipping to change at page 54, line 50 skipping to change at page 47, line 37
[RFC5461] Gont, F., "TCP's Reaction to Soft Errors", RFC 5461, [RFC5461] Gont, F., "TCP's Reaction to Soft Errors", RFC 5461,
DOI 10.17487/RFC5461, February 2009, DOI 10.17487/RFC5461, February 2009,
<http://www.rfc-editor.org/info/rfc5461>. <http://www.rfc-editor.org/info/rfc5461>.
[RFC6093] Gont, F. and A. Yourtchenko, "On the Implementation of the [RFC6093] Gont, F. and A. Yourtchenko, "On the Implementation of the
TCP Urgent Mechanism", RFC 6093, DOI 10.17487/RFC6093, TCP Urgent Mechanism", RFC 6093, DOI 10.17487/RFC6093,
January 2011, <http://www.rfc-editor.org/info/rfc6093>. January 2011, <http://www.rfc-editor.org/info/rfc6093>.
[RFC7414] Duke, M., Braden, R., Eddy, W., Blanton, E., and A. [RFC7414] Duke, M., Braden, R., Eddy, W., Blanton, E., and A.
Zimmermann, "A Roadmap for Transmission Control Protocol Zimmermann, "A Roadmap for Transmission Control Protocol
(TCP) Specification Documents", RFC 7414, (TCP) Specification Documents", RFC 7414, DOI 10.17487/
DOI 10.17487/RFC7414, February 2015, RFC7414, February 2015,
<http://www.rfc-editor.org/info/rfc7414>. <http://www.rfc-editor.org/info/rfc7414>.
[RFC7657] Black, D., Ed. and P. Jones, "Differentiated Services [RFC7657] Black, D., Ed. and P. Jones, "Differentiated Services
(Diffserv) and Real-Time Communication", RFC 7657, (Diffserv) and Real-Time Communication", RFC 7657,
DOI 10.17487/RFC7657, November 2015, DOI 10.17487/RFC7657, November 2015,
<http://www.rfc-editor.org/info/rfc7657>. <http://www.rfc-editor.org/info/rfc7657>.
[RFC8095] Fairhurst, G., Ed., Trammell, B., Ed., and M. Kuehlewind, [RFC8095] Fairhurst, G., Ed., Trammell, B., Ed., and M. Kuehlewind,
Ed., "Services Provided by IETF Transport Protocols and Ed., "Services Provided by IETF Transport Protocols and
Congestion Control Mechanisms", RFC 8095, Congestion Control Mechanisms", RFC 8095, DOI 10.17487/
DOI 10.17487/RFC8095, March 2017, RFC8095, March 2017,
<http://www.rfc-editor.org/info/rfc8095>. <http://www.rfc-editor.org/info/rfc8095>.
Appendix A. Overview of RFCs used as input for pass 1 Appendix A. Overview of RFCs used as input for pass 1
TCP: [RFC0793], [RFC1122], [RFC5482], [RFC5925], [RFC7413] TCP: [RFC0793], [RFC1122], [RFC5482], [RFC5925], [RFC7413]
MPTCP: [RFC6182], [RFC6824], [RFC6897] MPTCP: [RFC6182], [RFC6824], [RFC6897]
SCTP: RFCs without a socket API specification: [RFC3758], [RFC4895], SCTP: RFCs without a socket API specification: [RFC3758], [RFC4895],
[RFC4960], [RFC5061]. [RFC4960], [RFC5061].
RFCs that include a socket API specification: [RFC6458], RFCs that include a socket API specification: [RFC6458],
[RFC6525], [RFC6951], [RFC7053], [RFC7496] [RFC7829]. [RFC6525], [RFC6951], [RFC7053], [RFC7496] [RFC7829].
skipping to change at page 57, line 37 skipping to change at page 50, line 24
-02: included UDP, UDP-Lite, and all extensions of SCTPs. This -02: included UDP, UDP-Lite, and all extensions of SCTPs. This
includes fixing the [RFC6458] omission from -00. includes fixing the [RFC6458] omission from -00.
-03: wrote security considerations. The "how to contribute" section -03: wrote security considerations. The "how to contribute" section
was updated to reflect how the document WAS created, not how it was updated to reflect how the document WAS created, not how it
SHOULD BE created; it also no longer wrongly says that Experimental SHOULD BE created; it also no longer wrongly says that Experimental
RFCs are excluded. Included LEDBAT. Changed abstract and intro to RFCs are excluded. Included LEDBAT. Changed abstract and intro to
reflect which protocols/mechanisms are covered (TCP, MPTCP, SCTP, reflect which protocols/mechanisms are covered (TCP, MPTCP, SCTP,
UDP, UDP-Lite, LEDBAT) instead of talking about "transport UDP, UDP-Lite, LEDBAT) instead of talking about "transport
protocols". Interleaving and stream scheduling added (draft-ietf- protocols". Interleaving and stream scheduling added
tsvwg-sctp-ndata). TFO added. "Set protocol parameters" in SCTP (draft-ietf-tsvwg-sctp-ndata). TFO added. "Set protocol parameters"
replaced with per-parameter (or parameter group) primitives. More in SCTP replaced with per-parameter (or parameter group) primitives.
primitives added, mostly previously overlooked ones from [RFC6458]. More primitives added, mostly previously overlooked ones from
Updated terminology (s/transport service feature/transport feature) [RFC6458]. Updated terminology (s/transport service feature/
in line with an update of [RFC8095]. Made sequence of transport transport feature) in line with an update of [RFC8095]. Made
features / primitives more logical. Combined MPTCP's add/rem subflow sequence of transport features / primitives more logical. Combined
with SCTP's add/remove local address. MPTCP's add/rem subflow with SCTP's add/remove local address.
-04: changed UDP's close into an ABORT (to better fit with the -04: changed UDP's close into an ABORT (to better fit with the
primitives of TCP and SCTP), and incorporated the corresponding primitives of TCP and SCTP), and incorporated the corresponding
transport feature in step 3 (this addresses a comment from Gorry transport feature in step 3 (this addresses a comment from Gorry
Fairhurst). Added TCP Authentication (RFC 5925, section 7.1). Fairhurst). Added TCP Authentication (RFC 5925, section 7.1).
Changed TFO from looking like a primitive in pass 1 to be a part of Changed TFO from looking like a primitive in pass 1 to be a part of
'open'. Changed description of SCTP authentication in pass 3 to 'open'. Changed description of SCTP authentication in pass 3 to
encompass both TCP and SCTP. Added citations of [RFC8095] and minset encompass both TCP and SCTP. Added citations of [RFC8095] and minset
[I-D.draft-gjessing-taps-minset] to the intro, to give the context of [I-D.draft-gjessing-taps-minset] to the intro, to give the context of
this document. this document.
-05: minor fix to TCP authentication (comment from Joe Touch), -05: minor fix to TCP authentication (comment from Joe Touch),
several fixes from Gorry Fairhurst and Tom Jones. Language fixes; several fixes from Gorry Fairhurst and Tom Jones. Language fixes;
updated to align with latest taps-transport-usage-udp ID. updated to align with latest taps-transport-usage-udp ID.
-06: addressed WGLC comments from Aaron Falk and Tommy Pauly.
Authors' Addresses Authors' Addresses
Michael Welzl Michael Welzl
University of Oslo University of Oslo
PO Box 1080 Blindern PO Box 1080 Blindern
Oslo N-0316 Oslo, N-0316
Norway Norway
Email: michawe@ifi.uio.no Email: michawe@ifi.uio.no
Michael Tuexen Michael Tuexen
Muenster University of Applied Sciences Muenster University of Applied Sciences
Stegerwaldstrasse 39 Stegerwaldstrasse 39
Steinfurt 48565 Steinfurt 48565
Germany Germany
Email: tuexen@fh-muenster.de Email: tuexen@fh-muenster.de
Naeem Khademi Naeem Khademi
University of Oslo University of Oslo
PO Box 1080 Blindern PO Box 1080 Blindern
Oslo N-0316 Oslo, N-0316
Norway Norway
Email: naeemk@ifi.uio.no Email: naeemk@ifi.uio.no
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