draft-ietf-mmusic-sctp-sdp-09.txt   draft-ietf-mmusic-sctp-sdp-10.txt 
MMUSIC C. Holmberg MMUSIC C. Holmberg
Internet-Draft S. Loreto Internet-Draft S. Loreto
Intended status: Standards Track G. Camarillo Intended status: Standards Track G. Camarillo
Expires: June 8, 2015 Ericsson Expires: June 22, 2015 Ericsson
December 5, 2014 December 19, 2014
Stream Control Transmission Protocol (SCTP)-Based Media Transport in the Stream Control Transmission Protocol (SCTP)-Based Media Transport in the
Session Description Protocol (SDP) Session Description Protocol (SDP)
draft-ietf-mmusic-sctp-sdp-09 draft-ietf-mmusic-sctp-sdp-10
Abstract Abstract
SCTP (Stream Control Transmission Protocol) is a transport protocol SCTP (Stream Control Transmission Protocol) is a transport protocol
used to establish associations between two endpoints. used to establish associations between two endpoints.
This specification describes how to describe SCTP associations using This specification describes how to describe SCTP associations using
the Session Description Protocol (SDP), and defines the following new the Session Description Protocol (SDP), and defines the following new
SDP Media Description protocol identifiers (proto values):'SCTP', SDP Media Description protocol identifiers (proto values):'SCTP',
'SCTP/DTLS' and 'DTLS/SCTP'. 'SCTP/DTLS', 'UDP/DTLS/SCTP' and 'TCP/DTLS/SCTP'.
The specification also describes how to use the new proto values The specification also describes how to use the new proto values
together with the SDP Offer/Answer mechanism in order to negotiate together with the SDP Offer/Answer mechanism in order to negotiate
and establish SCTP associations, and how to indicate the SCTP and establish SCTP associations, and how to indicate the SCTP
application usage. application usage.
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.
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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 June 8, 2015. This Internet-Draft will expire on June 22, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. SCTP Terminology . . . . . . . . . . . . . . . . . . . . . . 4 3. SCTP Terminology . . . . . . . . . . . . . . . . . . . . . . 4
4. SDP Media Descriptions . . . . . . . . . . . . . . . . . . . 4 4. SDP Media Descriptions . . . . . . . . . . . . . . . . . . . 4
4.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.2. Protocol Identifiers . . . . . . . . . . . . . . . . . . 5 4.2. Protocol Identifiers . . . . . . . . . . . . . . . . . . 5
4.3. Media Format Management . . . . . . . . . . . . . . . . . 5 4.3. Media Format Management . . . . . . . . . . . . . . . . . 5
4.4. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.4. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.5. Example . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.5. Example . . . . . . . . . . . . . . . . . . . . . . . . . 6
5. SDP 'sctp-port' Attribute . . . . . . . . . . . . . . . . . . 6 5. SDP 'sctp-port' Attribute . . . . . . . . . . . . . . . . . . 6
5.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 6 5.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 7 5.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 6
6. SDP 'max-message-size' Attribute . . . . . . . . . . . . . . 7 6. SDP 'max-message-size' Attribute . . . . . . . . . . . . . . 7
6.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 7 6.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 7 6.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 7
7. SDP 'fmtp' Attribute . . . . . . . . . . . . . . . . . . . . 7 7. SDP 'fmtp' Attribute . . . . . . . . . . . . . . . . . . . . 7
7.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 7 7.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 7
7.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 8 7.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 8
8. SCTP Association Management . . . . . . . . . . . . . . . . . 8 8. UDP/DTLS/SCTP Transport Realization . . . . . . . . . . . . . 8
8.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 8 9. TCP/DTLS/SCTP Transport Realization . . . . . . . . . . . . . 8
8.2. SDP sendrecv/sendonly/sendrecv/inactive Attribute . . . . 8 10. SCTP Association Management . . . . . . . . . . . . . . . . . 8
8.3. SDP setup Attribute . . . . . . . . . . . . . . . . . . . 8 10.1. General . . . . . . . . . . . . . . . . . . . . . . . . 8
8.3.1. General . . . . . . . . . . . . . . . . . . . . . . . 8 10.2. SDP sendrecv/sendonly/sendrecv/inactive Attribute . . . 9
8.3.2. SCTP Association Initiation . . . . . . . . . . . . . 9 10.3. SDP setup Attribute . . . . . . . . . . . . . . . . . . 9
8.3.3. TLS Role Determination . . . . . . . . . . . . . . . 9 10.3.1. General . . . . . . . . . . . . . . . . . . . . . . 9
8.4. SDP connection Attribute . . . . . . . . . . . . . . . . 9 10.3.2. SCTP Association Initiation . . . . . . . . . . . . 9
9. SDP Offer/Answer Procedures . . . . . . . . . . . . . . . . . 10 10.3.3. TLS Role Determination . . . . . . . . . . . . . . . 9
9.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 10 10.4. SDP connection Attribute . . . . . . . . . . . . . . . . 10
9.2. Generating the Initial SDP Offer . . . . . . . . . . . . 11 11. SDP Offer/Answer Procedures . . . . . . . . . . . . . . . . . 10
9.3. Generating the SDP Answer . . . . . . . . . . . . . . . . 11 11.1. General . . . . . . . . . . . . . . . . . . . . . . . . 10
9.4. Offerer Processing of the SDP Answer . . . . . . . . . . 12 11.2. Generating the Initial SDP Offer . . . . . . . . . . . . 11
9.5. Modifying the Session . . . . . . . . . . . . . . . . . . 12 11.3. Generating the SDP Answer . . . . . . . . . . . . . . . 11
10. Multihoming Considerations . . . . . . . . . . . . . . . . . 13 11.4. Offerer Processing of the SDP Answer . . . . . . . . . . 12
11. NAT Considerations . . . . . . . . . . . . . . . . . . . . . 13 11.5. Modifying the Session . . . . . . . . . . . . . . . . . 13
11.1. General . . . . . . . . . . . . . . . . . . . . . . . . 13 12. Multihoming Considerations . . . . . . . . . . . . . . . . . 13
11.2. ICE Considerations . . . . . . . . . . . . . . . . . . . 13 13. NAT Considerations . . . . . . . . . . . . . . . . . . . . . 14
13.1. General . . . . . . . . . . . . . . . . . . . . . . . . 14
12. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 14 13.2. ICE Considerations . . . . . . . . . . . . . . . . . . . 14
13. Security Considerations . . . . . . . . . . . . . . . . . . . 14 14. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 14
14. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 15. Security Considerations . . . . . . . . . . . . . . . . . . . 14
14.1. New SDP proto values . . . . . . . . . . . . . . . . . . 14 16. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
14.2. New SDP Attribute . . . . . . . . . . . . . . . . . . . 14 16.1. New SDP proto values . . . . . . . . . . . . . . . . . . 14
14.3. association-usage Name Registry . . . . . . . . . . . . 15 16.2. New SDP Attribute . . . . . . . . . . . . . . . . . . . 15
15. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16 16.3. association-usage Name Registry . . . . . . . . . . . . 15
16. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 16 17. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16
17. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 18. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 16
17.1. Normative References . . . . . . . . . . . . . . . . . . 16 19. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
17.2. Informative References . . . . . . . . . . . . . . . . . 17 19.1. Normative References . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18 19.2. Informative References . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction 1. Introduction
SDP (Session Description Protocol) [RFC4566] provides a general- SDP (Session Description Protocol) [RFC4566] provides a general-
purpose format for describing multimedia sessions in announcements or purpose format for describing multimedia sessions in announcements or
invitations. TCP-Based Media Transport in the Session Description invitations. TCP-Based Media Transport in the Session Description
Protocol (SDP) [RFC4145] specifies a general mechanism for describing Protocol (SDP) [RFC4145] specifies a general mechanism for describing
and establishing TCP (Transmission Control Protocol) [RFC5246] and establishing TCP (Transmission Control Protocol) [RFC5246]
streams. Connection-Oriented Media Transport over the Transport streams. Connection-Oriented Media Transport over the Transport
Layer Security (TLS) Protocol in the Session Description Protocol Layer Security (TLS) Protocol in the Session Description Protocol
(SDP) [RFC4572] extends RFC4145 [RFC4145] for describing TCP-based (SDP) [RFC4572] extends RFC4145 [RFC4145] for describing TCP-based
media streams that are protected using TLS. media streams that are protected using TLS.
SCTP (Stream Control Transmission Protocol) is a transport protocol SCTP (Stream Control Transmission Protocol) is a transport protocol
used to establish associations between two endpoints. used to establish associations between two endpoints.
This specification describes how to describe SCTP associations using This specification describes how to describe SCTP associations using
the Session Description Protocol (SDP) [RFC4566], and defines the the Session Description Protocol (SDP) [RFC4566], and defines the
following new SDP Media Description [RFC4566] protocol identifiers following new SDP Media Description [RFC4566] protocol identifiers
(proto values):'SCTP', 'SCTP/DTLS' and 'DTLS/SCTP'. (proto values):'SCTP', 'SCTP/DTLS', 'UDP/DTLS/SCTP' and 'TCP/DTLS/
SCTP'.
The specification also describes how to use the new proto values The specification also describes how to use the new proto values
together with the SDP Offer/Answer mechanism [RFC3264] in order to together with the SDP Offer/Answer mechanism [RFC3264] in order to
negotiate and establish SCTP associations, and how to indicate the negotiate and establish SCTP associations, and how to indicate the
SCTP application usage. SCTP application usage.
NOTE: TLS is designed to run on top of a byte-stream oriented NOTE: TLS is designed to run on top of a byte-stream oriented
transport protocol providing a reliable, in-sequence delivery like transport protocol providing a reliable, in-sequence delivery like
TCP. [RFC6083] presents serious limitations with transporting SCTP TCP. [RFC6083] presents serious limitations with transporting SCTP
on top of TLS. Therefore, defining a mechanism to negotiate media on top of TLS. Therefore, defining a mechanism to negotiate media
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transport-layer port number. In the case of SCTP running over IP, a transport-layer port number. In the case of SCTP running over IP, a
transport address is defined by the combination of an IP address and transport address is defined by the combination of an IP address and
an SCTP port number (where SCTP is the transport protocol). an SCTP port number (where SCTP is the transport protocol).
4. SDP Media Descriptions 4. SDP Media Descriptions
4.1. General 4.1. General
This section defines the following new SDP Media Description (m- This section defines the following new SDP Media Description (m-
line) protocol identifiers (proto values) for describing an SCTP line) protocol identifiers (proto values) for describing an SCTP
association: 'SCTP', 'SCTP/DTLS' and 'DTLS/SCTP'. The section also association: 'SCTP', 'SCTP/DTLS', 'UDP/DTLS/SCTP' and 'TCP/DTLS/
describes how an m- line, associated with the proto values, is SCTP'. The section also describes how an m- line, associated with
created. the proto values, is created.
The following is the format for an 'm' line, as specified in RFC4566 The following is the format for an 'm' line, as specified in RFC4566
[RFC4566]: [RFC4566]:
m=<media> <port> <proto> <fmt> ... m=<media> <port> <proto> <fmt> ...
The 'SCTP', 'SCTP/DTLS' and 'DTLS/SCTP' proto values are similar to The 'SCTP', 'SCTP/DTLS', 'UDP/DTLS/SCTP' and 'TCP/DTLS/SCTP' proto
both the 'UDP' and 'TCP' proto values in that they only describe the values are similar to both the 'UDP' and 'TCP' proto values in that
transport protocol and not the upper-layer protocol. they only describe the transport-layer protocol and not the upper-
layer protocol.
NOTE: When the 'DTLS/SCTP' proto value is used, the underlying NOTE: When the 'UDP/DTLS/SCTP' and 'TCP/DTLS/SCTP' proto values are
transport protocol is either UDP or TCP. used, the underlying transport protocol is either UDP or TCP, SCTP is
carried on top of either of those transport-layer protocols.
The m- line fmt value, identifying the application-layer protocol, The m- line fmt value, identifying the application-layer protocol,
MUST be registered by IANA. MUST be registered by IANA.
4.2. Protocol Identifiers 4.2. Protocol Identifiers
The new proto values are defined as below: The new proto values are defined as below:
o The 'SCTP' proto value describes an SCTP association, as defined o The 'SCTP' proto value describes an SCTP association, as defined
in [RFC4960]. in [RFC4960].
o The 'SCTP/DTLS' proto value describes a Datagram Transport Layer o The 'SCTP/DTLS' proto value describes a Datagram Transport Layer
Security (DTLS) [RFC6347] connection on top of an SCTP Security (DTLS) [RFC6347] connection on top of an SCTP
association, as defined in [RFC6083]. association, as defined in [RFC6083].
o The 'DTLS/SCTP' proto value describes an SCTP association on top o The 'UDP/DTLS/SCTP' proto value describes an SCTP association on
of a DTLS connection, as defined in top of a DTLS connection on top of UDP, as defined in Section 8.
[I-D.ietf-tsvwg-sctp-dtls-encaps].
NOTE: In the case of 'DTLS/SCTP', the actual transport protocol below
DTLS is either UDP or TCP.
OPEN ISSUE #1: It is FFS whether separate proto values will be used, o The 'TCP/DTLS/SCTP' proto value describes an SCTP association on
depending on whether the underlying transport protocol is UDP (e.g. top of a DTLS connection on top of TCP, as defined in Section 9.
'UDP/DTLS/SCTP') or TCP (e.g. 'TCP/DTLS/SCTP').
4.3. Media Format Management 4.3. Media Format Management
[RFC4566] defines that specifications defining new proto values must [RFC4566] defines that specifications defining new proto values must
define the rules by which their media format (fmt) namespace is define the rules by which their media format (fmt) namespace is
managed. Use of an existing MIME subtype for the format is managed. Use of an existing MIME subtype for the format is
encouraged. If no MIME subtype exists, it is recommended that a encouraged. If no MIME subtype exists, it is recommended that a
suitable one is registered through the IETF process [RFC6838] suitable one is registered through the IETF process [RFC6838]
[RFC4289] by production of, or reference to, a standards-track RFC [RFC4289] by production of, or reference to, a standards-track RFC
that defines the transport protocol for the format. that defines the transport protocol for the format.
An m- line with a proto value of 'SCTP', 'SCTP/DTLS' or 'DTLS/SCTP' An m- line with a proto value of 'SCTP', 'SCTP/DTLS', 'UDP/DTLS/SCTP'
always describe a single SCTP association. or 'TCP/DTLS/SCTP' always describe a single SCTP association.
In addition, such m- line MUST further indicate the application-layer In addition, such m- line MUST further indicate the application-layer
protocol using an 'fmt' identifier. There MUST be exactly one 'fmt' protocol using an 'fmt' identifier. There MUST be exactly one 'fmt'
value per m- line associated with the proto values defined in this value per m- line associated with the proto values defined in this
specification. The "fmt" namespace associated with those proto specification. The "fmt" namespace associated with those proto
values describes the generic application usage of the entire SCTP values describes the generic application usage of the entire SCTP
association, including the associated SCTP streams. association, including the associated SCTP streams.
NOTE: A mechanism on how to describe, and manage, individual SCTP NOTE: A mechanism on how to describe, and manage, individual SCTP
streams within an SCTP association, is outside the scope of this streams within an SCTP association, is outside the scope of this
specification. specification.
4.4. Syntax 4.4. Syntax
sctp-m-line = %x6d "=" sctp-m-line = %x6d "="
("application" SP sctp-port SP "SCTP" SP sctp-fmt CRLF) / ("application" SP sctp-port SP "SCTP" SP sctp-fmt CRLF) /
("application" SP sctp-port SP "SCTP/DTLS" SP sctp-fmt CRLF) / ("application" SP sctp-port SP "SCTP/DTLS" SP sctp-fmt CRLF) /
("application" SP udp-port SP "DTLS/SCTP" SP sctp-fmt CRLF) ("application" SP udp-port SP "UDP/DTLS/SCTP" SP sctp-fmt CRLF) /
("application" SP udp-port SP "TCP/DTLS/SCTP" SP sctp-fmt CRLF)
sctp-port = port sctp-port = port
udp-port = port udp-port = port
sctp-fmt = association-usage sctp-fmt = association-usage
association-usage = token association-usage = token
4.5. Example 4.5. Example
TEMP: m=application 12345 UDP/DTLS/SCTP webrtc-datachannel
m=application 12345 DTLS/SCTP webrtc-datachannel a=max-message-size: 100000
a=max-message-size=100000
m=application 12345 DTLS/SCTP webrtc-datachannel
a=fmtp:webrtc-datachannel max-message-size=100000
5. SDP 'sctp-port' Attribute 5. SDP 'sctp-port' Attribute
5.1. General 5.1. General
This section defines a new SDP media-level attribute, 'sctp-port'. This section defines a new SDP media-level attribute, 'sctp-port'.
The attribute can be associated with an SDP media descriptor (m- The attribute can be associated with an SDP media descriptor (m-
line) with a 'DTLS/SCTP' proto value, in which case the m- line port line) with a 'UDP/DTLS/SCTP' or a 'TCP/DTLS/SCTP' proto value, in
value indicates the port of the underlying transport protocol (UDP or which case the m- line port value indicates the port of the
TCP). transport-layer protocol (UDP or TCP), on which SCTP is carried.
TEMP: If the SDP sctp-port attribute is not present, the m- line If the SDP sctp-port attribute is not present, the m- line MUST be
SHOULD be discarded. If the SDP sctp-port attribute is not present, discarded.
the default value is 5000.
Usage of the SDP sctp-port attribute with other proto values is not Usage of the SDP sctp-port attribute with other proto values is not
specified, and MUST be discarded if received. specified, and MUST be discarded if received.
5.2. Syntax 5.2. Syntax
sctp-port-attr = "a=sctp-port:" port sctp-port-attr = "a=sctp-port:" port
port = 1*DIGIT port = 1*DIGIT
6. SDP 'max-message-size' Attribute 6. SDP 'max-message-size' Attribute
6.1. General 6.1. General
The SDP 'max-message-size' attribute can be associated with an m- The SDP 'max-message-size' attribute can be associated with an m-
line to indicate the maximum message size that an SCTP endpoint is line to indicate the maximum message size that an SCTP endpoint is
willing to receive on the SCTP association associated with the m- willing to receive on the SCTP association associated with the m-
line. line.
The remote peer MUST assume that larger messages will be rejected by The remote peer MUST assume that larger messages will be rejected by
the SCTP endpoint. SCTP endpoints need to decide on appropriate the SCTP endpoint. SCTP endpoints need to decide on appropriate
behaviour in case a message that exceeds the maximum size needs to be behavior in case a message that exceeds the maximum size needs to be
sent. sent.
If the SDP 'max-message-size' attribute contains a maximum message If the SDP 'max-message-size' attribute contains a maximum message
size value of zero, it indicates the SCTP endpoint will handle size value of zero, it indicates the SCTP endpoint will handle
messages of any size, subject to memory capacity etc. messages of any size, subject to memory capacity etc.
If the SDP 'max-message-size' attribute is not present, the default If the SDP 'max-message-size' attribute is not present, the default
value is 64K. value is 64K.
6.2. Syntax 6.2. Syntax
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7.1. General 7.1. General
The SDP 'fmtp' attribute can be used with an m- line, associated with The SDP 'fmtp' attribute can be used with an m- line, associated with
an SCTP association, to indicate the maximum message size that an an SCTP association, to indicate the maximum message size that an
SCTP endpoint is willing to receive, for a particular SCTP SCTP endpoint is willing to receive, for a particular SCTP
association usage, on that SCTP association. association usage, on that SCTP association.
The remote peer MUST assume that larger messages will be rejected by The remote peer MUST assume that larger messages will be rejected by
the SCTP endpoint. SCTP endpoints need to decide on appropriate the SCTP endpoint. SCTP endpoints need to decide on appropriate
behaviour in case a message that exceeds the maximum size needs to be behavior in case a message that exceeds the maximum size needs to be
sent. sent.
If the SDP 'fmtp' attribute contains a maximum message size value of If the SDP 'fmtp' attribute contains a maximum message size value of
zero, it indicates the SCTP endpoint will handle messages of any zero, it indicates the SCTP endpoint will handle messages of any
size, subject to memory capacity etc. size, subject to memory capacity etc.
If the SDP 'fmtp' attribute is not present, the default value is 64K. If the SDP 'fmtp' attribute is not present, the default value is 64K.
NOTE: This specification only defines the usage of the SDP 'max- NOTE: This specification only defines the usage of the SDP 'max-
message-size' attribute when associated with an m- line containing message-size' attribute when associated with an m- line containing
one of the following proto field values: 'SCTP', 'SCTP/DTLS' or one of the following proto field values: 'SCTP', 'SCTP/DTLS',
'DTLS/SCTP'. Usage of the attribute with other proto field values 'UDP/DTLS/SCTP' or 'TCP/DTLS/SCTP'. Usage of the attribute with
needs to be defined in a separate specification. other proto values needs to be defined in a separate specification.
7.2. Syntax 7.2. Syntax
sctpmap-attr = "a=fmtp:" association-usage [max-message-size] sctpmap-attr = "a=fmtp:" association-usage [max-message-size]
max-message-size = "max-message-size" EQUALS 1*DIGIT max-message-size = "max-message-size" EQUALS 1*DIGIT
8. SCTP Association Management 8. UDP/DTLS/SCTP Transport Realization
8.1. General The UDP/DTLS/SCTP transport is realized as described below:
o SCTP on top of DTLS is realized according to the procedures
defined in [I-D.ietf-tsvwg-sctp-dtls-encaps]; and
o DTLS on top of UDP is realized according to the procedures in
defined in [RFC6347].
9. TCP/DTLS/SCTP Transport Realization
The TCP/DTLS/SCTP transport is realized as described below:
o SCTP on top of DTLS is realized according to the procedures
defined in [I-D.ietf-tsvwg-sctp-dtls-encaps]; and
o DTLS on top of TCP is realized using the framing method defined in
[RFC4571].
NOTE: DTLS on top of TCP, without using the framing method defined in
[RFC4571] is outside the scope of this specification. A separate
proto value would need to be registered for such transport
realization.
10. SCTP Association Management
10.1. General
The management of an SCTP association is identical to the management The management of an SCTP association is identical to the management
of a TCP connection. An SCTP endpoints MUST follow the rules in of a TCP connection. An SCTP endpoints MUST follow the rules in
Section 6 of [RFC4145] to manage SCTP associations. Whether to use Section 6 of [RFC4145] to manage SCTP associations. Whether to use
the SCTP ordered or unordered delivery service is up to the the SCTP ordered or unordered delivery service is up to the
applications using the SCTP association, and this specification does applications using the SCTP association, and this specification does
not define a mechanism to indicate the type of delivery service using not define a mechanism to indicate the type of delivery service using
SDP. SDP.
8.2. SDP sendrecv/sendonly/sendrecv/inactive Attribute 10.2. SDP sendrecv/sendonly/sendrecv/inactive Attribute
This specification does not define any semantics for the SDP This specification does not define semantics for the SDP direction
direction attributes [RFC4566]. Specifications for an individual attributes [RFC4566]. Specifications for an individual SCTP
SCTP association usage MAY define how the attributes can be used with association usage MAY define how the attributes can be used with that
that association usage. If the semantics of these attributes for an usage. Unless semantics of these attributes for an SCTP association
SCTP association usage has not been defined, SDP direction attributes usage have been defined, SDP direction attributes MUST be discarded
MUST be discarded if present. if present.
8.3. SDP setup Attribute 10.3. SDP setup Attribute
8.3.1. General 10.3.1. General
The SDP setup attribute is used to determine the 'active/passive' The SDP setup attribute is used to determine the 'active/passive'
status of the endpoints, following the procedures for TCP in status of the endpoints, following the procedures for TCP in
[RFC4145]. [RFC4145].
8.3.2. SCTP Association Initiation 10.3.2. SCTP Association Initiation
Both the 'active' and 'passive' endpoint MUST initiate the SCTP Both the 'active' and 'passive' endpoint MUST initiate the SCTP
association, and MUST use the same SCTP port as client port and association, and MUST use the same SCTP port as client port and
server port (in order to prevent two separate SCTP associations from server port (in order to prevent two separate SCTP associations from
being established). being established).
NOTE: The procedure above is different from TCP, where only the NOTE: The procedure above is different from TCP, where only the
'active' endpoint initiates the TCP connection [RFC4145]. 'active' endpoint initiates the TCP connection [RFC4145].
If the m- line proto field value is 'DTLS/SCTP', and if SCTP is If the m- line proto value is 'TCP/DTLS/SCTP', only the 'active'
carried on top of TCP, only the 'active' endpoint will initiate the endpoint will initiate the TCP connection, following the procedures
TCP connection, following the procedures in [RFC4145], while both in [RFC4145]. Both endpoints will still initiate the SCTP
endpoints will initiate the SCTP association carried on top of the association on top of the TCP connection.
TCP connection.
8.3.3. TLS Role Determination 10.3.3. TLS Role Determination
If the m- line proto field value is 'SCTP/DTLS' or 'DTLS/SCTP', the If the m- line proto value is 'SCTP/DTLS', 'UDP/DTLS/SCTP' or
'active/passive' status is used to determine the TLS roles. 'TCP/DTLS/SCTP', the 'active/passive' status is used to determine the
Following the procedures in [RFC4572], the 'active' endpoint will TLS roles of the endpoints. Following the procedures in [RFC4572],
take the TLS client role. the 'active' endpoint will take the TLS client role.
Once a DTLS connection has been established, if the 'active/passive' Once a DTLS connection has been established, if the 'active/passive'
status of the endpoints change during a session, a new DTLS status of the endpoints change (as result of an offer/answer
connection MUST be established. Therefore, endpoints SHOULD NOT transaction) during a session, a new DTLS connection MUST be
change the 'active/passive' status in subsequent offers and answers, established. Therefore, endpoints SHOULD NOT change the 'active/
unless they want to establish a new DTLS connection. passive' status during a session, unless they want to establish a new
DTLS connection.
If the transport parameters or the key fingerprints change, the If the transport parameters or the key fingerprints change, the
endpoints MUST establish a new DTLS connection. In such case the endpoints MUST establish a new DTLS connection. In such case the
'active/passive' status of the endpoints will again be determined 'active/passive' status of the endpoints will again be determined
following the procedures in [RFC4145], and the new status will be following the procedures in [RFC4145], and the new status will be
used to determine the TLS roles associated with the new DTLS used to determine the TLS roles of the endpoints associated with the
connection. new DTLS connection.
NOTE: The procedure above is identical to the one defined for SRTP- NOTE: The procedure above is identical to the one defined for SRTP-
DTLS in [RFC5763]. DTLS in [RFC5763].
NOTE: A new DTLS connection needs to be established if the transport 10.4. SDP connection Attribute
parameters or the key fingerprints change.
8.4. SDP connection Attribute
The SDP connection attribute is used following the procedures in The SDP connection attribute is used following the procedures in
[RFC4145], with the additional SCTP specific considerations described [RFC4145], with the additional SCTP specific considerations described
in this section. in this section.
The SDP connection attribute only applies to an SCTP association and, If the m- line proto value is 'TCP/DTLS/SCTP', an SDP connection
if the m- line proto field value is 'DTLS/SCTP', also to the TCP attribute associated with that m- line applies to both the SCTP
connection which is used to carry the SCTP association. An attribute association and the TCP connection. Therefore, an attribute 'new'
'new' value indicates that a new SCTP association (and, if value indicates that both a new SCTP association, and a new TCP
applicable, the TCP connection, have to be established, following the connection, have to be established, following the procedures in
procedures in [RFC4145]. [RFC4145].
OPEN ISSUE #3: We need to determine whether the SDP connection
attribute only applies to the transport-layer protocol, and not e.g.
to an SCTP assocation carried on top of UDP or TCP.
The SDP connection attribute value does not impact an existing DTLS NOTE: This specification does not define a mechanism which allows re-
connection. Section 8.3.3 describes in which cases a new DTLS establishing of a new SCTP association, while maintaining the TCP
connections will be established. connection.
NOTE: if the m- line proto field value is 'SCTP/DTLS', and if the The SDP connection attribute value does not automatically impact an
SCTP association is re-established, the DTLS connection also needs to existing DTLS connection. Section 10.3.3 describes in which cases a
be re-established. new DTLS connections will be established.
OPEN ISSUE #2: Verify that the above statement regarding 'SCTP/DTLS' NOTE: If the m- line proto value is 'SCTP/DTLS', and if the SCTP
is correct. association is re-established, the DTLS connection also needs to be
re-established.
9. SDP Offer/Answer Procedures 11. SDP Offer/Answer Procedures
9.1. General 11.1. General
This section defines the SDP Offer/Answer [RFC3264] procedures for This section defines the SDP Offer/Answer [RFC3264] procedures for
negotiating and establishing an SCTP association. Unless explicitly negotiating and establishing an SCTP association. Unless explicitly
stated, the procedures apply to all m- line proto values ('SCTP', stated, the procedures apply to all m- line proto values ('SCTP',
'SCTP/DTLS' and 'DTLS/SCTP') defined in this specification. 'SCTP/DTLS', 'UDP/DTLS/SCTP' and 'TCP/DTLS/SCTP') defined in this
specification.
If the m- line proto value is 'SCTP/DTLS' or 'DTLS/SCTP', each If the m- line proto value is 'SCTP/DTLS', 'UDP/DTLS/SCTP' or
endpoint MUST provide a certificate fingerprint, using the SDP 'TCP/DTLS/SCTP', each endpoint MUST provide a certificate
'fingerprint' attribute [RFC4145], if the endpoint supports, and is fingerprint, using the SDP 'fingerprint' attribute [RFC4145], if the
willing to use, a cipher suite with an associated certificate. endpoint supports, and is willing to use, a cipher suite with an
associated certificate.
The authentication certificates are interpreted and validated as The authentication certificates are interpreted and validated as
defined in [RFC4572]. Self-signed certificates can be used securely, defined in [RFC4572]. Self-signed certificates can be used securely,
provided that the integrity of the SDP description is assured as provided that the integrity of the SDP description is assured as
defined in [RFC4572]. defined in [RFC4572].
NOTE: The procedures apply to a specific m- line describing an SCTP NOTE: The procedures apply to a specific m- line describing an SCTP
association. If an offer or answer contains multiple m- line association. If an offer or answer contains multiple m- lines
describing SCTP associations, the procedures are applied separately describing SCTP associations, the procedures are applied separately
to each m- line. to each m- line.
9.2. Generating the Initial SDP Offer 11.2. Generating the Initial SDP Offer
When the offerer creates an initial offer, the offerer: When the offerer creates an initial offer, the offerer:
o MUST, if the m- line proto field value is 'SCTP/DTLS' or 'DTLS/ o MUST, if the m- line proto value is 'SCTP/DTLS', 'UDP/DTLS/SCTP'
SCTP', associate an SDP setup attribute [Section 8.3], with an or 'TCP/DTLS/SCTP', associate an SDP setup attribute
'actpass' value, with the m- line; [Section 10.3], with an 'actpass' value, with the m- line;
o MUST, if the m- line proto field is 'DTLS/SCTP', associate an SDP o MUST, if the m- line proto is 'UDP/DTLS/SCTP' or 'TCP/DTLS/SCTP',
sctp-port attribute[Section 5] with the m- line; associate an SDP 'sctp-port' attribute [Section 5] with the m-
line;
o MUST associate an SDP 'connection' attribute [Section 8.4], with a o MUST associate an SDP 'connection' attribute [Section 10.4], with
'new' value, with the m- line; and a 'new' value, with the m- line; and
o MAY associate an SDP 'max-message-size' attribute [Section 7] with o MAY associate an SDP 'max-message-size' attribute [Section 7] with
the m- line. the m- line.
9.3. Generating the SDP Answer 11.3. Generating the SDP Answer
When the answerer receives an offer, which contains an m- line When the answerer receives an offer, which contains an m- line
describing an SCTP association, if the answerer accepts the m- line describing an SCTP association, if the answerer accepts the m- line
it: it:
o MUST insert a corresponiding m- line in the answer, with an o MUST insert a corresponding m- line in the answer, with an
identical m- line proto value [RFC3264]; identical m- line proto value [RFC3264];
o MUST, if the m- line proto field value is 'SCTP/DTLS' or 'DTLS/ o MUST, if the m- line proto value is 'SCTP/DTLS', 'UDP/DTLS/SCTP'
SCTP', associate an SDP setup attribute [Section 8.3], with an or 'TCP/DTLS/SCTP', associate an SDP 'setup' attribute
'active' or 'passive' value, with the m- line; [Section 10.3], with an 'active' or 'passive' value, with the m-
line;
o MUST, if the m- line proto field is 'DTLS/SCTP', associate an SDP o MUST, if the m- line proto is 'UDP/DTLS/SCTP' or 'TCP/DTLS/SCTP',
sctp-port attribute[Section 5] with the m- line; associate an SDP 'sctp-port' attribute[Section 5] with the m-
line; and
o MAY associate an SDP 'max-message-size' attribute [Section 7] with o MAY associate an SDP 'max-message-size' attribute [Section 7] with
the m- line. the m- line.
Once the answerer has sent the answer, the answerer: Once the answerer has sent the answer, the answerer:
o MUST, if an SCTP association associated with the m- line has yet o MUST, if an SCTP association associated with the m- line has yet
not been established, or if an existing SCTP association is to be not been established, or if an existing SCTP association is to be
re-established, initiate the establishing of the SCTP association; re-established, initiate the establishing of the SCTP association;
and and
skipping to change at page 12, line 10 skipping to change at page 12, line 25
o MUST, if the answerer is the 'active' endpoint, and if an DTLS o MUST, if the answerer is the 'active' endpoint, and if an DTLS
connection associated with the m- line is to be established (or connection associated with the m- line is to be established (or
re-established), initiate the establishing of the DTLS connection re-established), initiate the establishing of the DTLS connection
(by sending a ClientHello message). (by sending a ClientHello message).
If the answerer does not accept the m- line in the offer, it MUST If the answerer does not accept the m- line in the offer, it MUST
assign a zero port value to the corresponding m- line in the answer. assign a zero port value to the corresponding m- line in the answer.
In addition, the answerer MUST NOT establish an SCTP association, or In addition, the answerer MUST NOT establish an SCTP association, or
a DTLS connection, associated with the m- line. a DTLS connection, associated with the m- line.
9.4. Offerer Processing of the SDP Answer 11.4. Offerer Processing of the SDP Answer
When the offerer receives an answer, which contains an m- line with a When the offerer receives an answer, which contains an m- line with a
non-zero port value, describing an SCTP association, the offerer: non-zero port value, describing an SCTP association, the offerer:
o MUST, if the offerer is the 'active' endpoint, if the m- line
proto is 'TCP/DTLS/SCTP', and if a TCP connection used to carry
the SCTP association has yet not been established (or if an
existing TCP connection is to be re-established), initiate the
establishing of the TCP connection;
o MUST, if an SCTP association associated with the m- line has yet o MUST, if an SCTP association associated with the m- line has yet
not been established, or if an existing SCTP association is to be not been established (or if an existing SCTP association is to be
re-established, initiate the establishing of the SCTP association; re-established), initiate the establishing of the SCTP
and association; and
o MUST, if the offerer is the 'active' endpoint, and if an DTLS o MUST, if the offerer is the 'active' endpoint, and if an DTLS
connection associated with the m- line is to be established (or connection associated with the m- line is to be established (or if
re-established), initiate the establishing of the DTLS connection an existing DTLS connection is to be re-established), initiate the
(by sending a ClientHello message). establishing of the DTLS connection (by sending a ClientHello
message).
If the m- line in the answer contains a zero port value, the offerer If the m- line in the answer contains a zero port value, the offerer
MUST NOT establish an SCTP association, or a DTLS connection, MUST NOT establish a TCP connection, an SCTP association, or a DTLS
associated with the m- line. connection, associated with the m- line.
9.5. Modifying the Session 11.5. Modifying the Session
When an offerer sends an updated offer, in order to modify a When an offerer sends an updated offer, in order to modify a
previously established SCTP assiciation, it follows the procedures in previously established SCTP association, it follows the procedures in
Section 9.2, with the following exceptions: Section 11.2, with the following exceptions:
o Unless the offerer wants to re-establish an existing SCTP o Unless the offerer wants to re-establish an existing SCTP
association, the offerer MUST associate an SDP connection association, the offerer MUST associate an SDP connection
attribute, with an 'existing' value, with the m- line; and attribute, with an 'existing' value, with the m- line; and
o If the offerer wants to disable a previously established SCTP o If the offerer wants to disable a previously established SCTP
association, it MUST assign a zero port value to the m- line association, it MUST assign a zero port value to the m- line
associated with the SCTP association, following the procedures in associated with the SCTP association, following the procedures in
[RFC3264]. [RFC3264].
NOTE: Different SCTP association usages might define protocol NOTE: Different SCTP association usages might define protocol
procedures etc that need to be performed before an SCTP association procedures etc that need to be performed before an SCTP association
is terminated. Such procedures are outside the scope of this is terminated. Such procedures are outside the scope of this
specification. specification.
10. Multihoming Considerations 12. Multihoming Considerations
SCTP supports multihoming. An SCTP endpoint is considered multihomed SCTP supports multihoming. An SCTP endpoint is considered multihomed
if it has more than one IP address on which SCTP can be used. An if it has more than one IP address on which SCTP can be used. An
SCTP endpoint inform the remote peer about its IP addresses using the SCTP endpoint inform the remote peer about its IP addresses using the
address parameters in the INIT/INIT-ACK chunk. Therefore, when SDP address parameters in the INIT/INIT-ACK chunk. Therefore, when SDP
is used to describe an SCTP association, while the "c=" line contains is used to describe an SCTP association, while the "c=" line contains
the address which was used to negotiate the SCTP association, the address which was used to negotiate the SCTP association,
multihomed SCTP endpoints might end up using other IP addresses. multihomed SCTP endpoints might end up using other IP addresses.
If an endpoint removes the IP address [RFC5061] that it offered in If an endpoint removes the IP address [RFC5061] that it offered in
skipping to change at page 13, line 31 skipping to change at page 14, line 5
and firewall control use the address information in the SDP "c=" and and firewall control use the address information in the SDP "c=" and
"m=" lines to authorize media, and will not pass media sent using "m=" lines to authorize media, and will not pass media sent using
other addresses. In such network environment, if an SCTP endpoints other addresses. In such network environment, if an SCTP endpoints
wants to change the address information on which media is sent and wants to change the address information on which media is sent and
received, it needs to send an updated Offer, in which the SDP "c=" received, it needs to send an updated Offer, in which the SDP "c="
and "m=" lines contain the new address information. and "m=" lines contain the new address information.
Multihoming is not supported when sending SCTP on top of DTLS, as Multihoming is not supported when sending SCTP on top of DTLS, as
DTLS does not expose address management to its upper layer. DTLS does not expose address management to its upper layer.
11. NAT Considerations 13. NAT Considerations
11.1. General 13.1. General
SCTP features not present in UDP or TCP, including the checksum SCTP features not present in UDP or TCP, including the checksum
(CRC32c) value calculated on the whole packet (rather than just the (CRC32c) value calculated on the whole packet (rather than just the
header), and multihoming, introduce new challenges for NAT traversal. header), and multihoming, introduce new challenges for NAT traversal.
[I-D.ietf-behave-sctpnat] defines an SCTP specific variant of NAT, [I-D.ietf-behave-sctpnat] defines an SCTP specific variant of NAT,
which provides similar features of Network Address and Port which provides similar features of Network Address and Port
Translation (NAPT). Translation (NAPT).
Current NATs typically do not support SCTP. [RFC6951] defines a Current NATs typically do not support SCTP. [RFC6951] defines a
mechanism for sending SCTP on top of UDP, which makes it possible to mechanism for sending SCTP on top of UDP, which makes it possible to
use SCTP with NATs and firewalls that do not support SCTP. use SCTP with NATs and firewalls that do not support SCTP.
11.2. ICE Considerations 13.2. ICE Considerations
At the time of writing this specification, no procedures have been At the time of writing this specification, no procedures have been
defined for using ICE ICE (Interactive Connectivity Establishment) defined for using ICE (Interactive Connectivity Establishment)
[RFC5768] together with SCTP. Such procedures, including the [RFC5768] together with SCTP. Such procedures, including the
associated SDP Offer/Answer procedures, are outside the scope of this associated SDP Offer/Answer procedures, are outside the scope of this
specification, and might be defined in a future specification. specification, and might be defined in a future specification.
12. Examples 14. Examples
TODO: ADD EXAMPLES HERE TODO: ADD EXAMPLES HERE
13. Security Considerations 15. Security Considerations
[RFC4566] defines general SDP security considerations, while [RFC4566] defines general SDP security considerations, while
[RFC3264], [RFC4145] and [RFC4572] define security considerations [RFC3264], [RFC4145] and [RFC4572] define security considerations
when using the SDP Offer/Answer mechanism to negotiate media streams. when using the SDP offer/answer mechanism to negotiate media streams.
[RFC4960] defines general SCTP security considerations. security [RFC4960] defines general SCTP security considerations. security
considerations on SCTP in general, while [RFC6083] defines security considerations on SCTP in general, while [RFC6083] defines security
considerations when using DTLS on top of SCTP. considerations when using DTLS on top of SCTP.
This specification does not introduce new security considerations in This specification does not introduce new security considerations in
addition to those defined in the specifications listed above. addition to those defined in the specifications listed above.
14. IANA Considerations 16. IANA Considerations
14.1. New SDP proto values 16.1. New SDP proto values
[RFC EDITOR NOTE: Please replace RFCXXXX with the RFC number of this [RFC EDITOR NOTE: Please replace RFCXXXX with the RFC number of this
document.] document.]
This document updates the "Session Description Protocol (SDP) This document updates the "Session Description Protocol (SDP)
Parameters" registry, following the procedures in [RFC4566], by Parameters" registry, following the procedures in [RFC4566], by
adding the following values to the table in the SDP "proto" field adding the following values to the table in the SDP "proto" field
registry: registry:
+-------+-----------+-----------+ +---------------+---------------+-----------+
| Type | SDP Name | Reference | | Type | SDP Name | Reference |
+-------+-----------+-----------+ +---------------+---------------+-----------+
| proto | SCTP | [RFCXXXX] | | proto | SCTP | [RFCXXXX] |
| proto | SCTP/DTLS | [RFCXXXX] | | proto | SCTP/DTLS | [RFCXXXX] |
| proto | DTLS/SCTP | [RFCXXXX] | | proto | UDP/DTLS/SCTP | [RFCXXXX] |
+-------+-----------+-----------+ | TCP/DTLS/SCTP | [RFCXXXX] |
+---------------+---------------+-----------+
Table 1: SDP "proto" field values Table 1: SDP "proto" field values
14.2. New SDP Attribute 16.2. New SDP Attribute
[RFC EDITOR NOTE: Please replace RFCXXXX with the RFC number of this [RFC EDITOR NOTE: Please replace RFCXXXX with the RFC number of this
document.] document.]
This document defines a new SDP media-level attribute,'sctp-port', as This document defines a new SDP media-level attribute,'sctp-port', as
follows: follows:
Attribute name: sctp-port Attribute name: sctp-port
Type of attribute: media Type of attribute: media
Subject to charset: No Subject to charset: No
Purpose: Indicate the SCTP port value associated Purpose: Indicate the SCTP port value associated
with the SDP Media Description. with the SDP Media Description.
Appropriate values: Integer Appropriate values: Integer
Contact name: Christer Holmberg Contact name: Christer Holmberg
Contact e-mail: christer.holmberg@ericsson.com Contact e-mail: christer.holmberg@ericsson.com
Reference: RFCXXXX Reference: RFCXXXX
14.3. association-usage Name Registry 16.3. association-usage Name Registry
[RFC EDITOR NOTE: Please replace RFCXXXX with the RFC number of this [RFC EDITOR NOTE: Please replace RFCXXXX with the RFC number of this
document.] document.]
This specification creates a new IANA registry, following the This specification creates a new IANA registry, following the
procedures in [RFC5226], for the "fmt" namespace associated with the procedures in [RFC5226], for the "fmt" namespace associated with the
'SCTP', 'SCTP/DTLS' and 'DTLS/SCTP' protocol identifiers. Each "fmt" 'SCTP', 'SCTP/DTLS', 'UDP/DTLS/SCTP' and 'TCP/DTLS/SCTP' protocol
value describes the usage of an entire SCTP association, including identifiers. Each "fmt" value describes the usage of an entire SCTP
all SCTP streams associated with the SCTP association. association, including all SCTP streams associated with the SCTP
association.
NOTE: Usage indication of individual SCTP streams is outside the NOTE: Usage indication of individual SCTP streams is outside the
scope of this specification. scope of this specification.
The "fmt" value, "association-usage", used with these "proto" is The "fmt" value, "association-usage", used with these "proto" is
required. It is defined in section Section 4. required. It is defined in [Section 4].
As part of this registry, IANA maintains the following information: As part of this registry, IANA maintains the following information:
association-usage Name: .The identifier of the subprotocol, as will association-usage Name: .The identifier of the subprotocol, as will
be used in the <sctp-fmtp> subfield. be used in the <sctp-fmtp> subfield.
association-usage reference: A reference to the document in which association-usage reference: A reference to the document in which
the the association usage is defined. the association usage is defined.
association-usage names are to be subject to the "First Come First association-usage names are to be subject to the "First Come First
Served" IANA registration policy [RFC5226]. Served" IANA registration policy [RFC5226].
IANA is asked to add initial values to the registry. IANA is asked to add initial values to the registry.
| name | Reference | | name | Reference |
-+--------------------+-------------------------------------+ -+--------------------+-------------------------------------+
| webrtc-datachannel | draft-ietf-rtcweb-data-protocol-xx | | webrtc-datachannel | draft-ietf-rtcweb-data-protocol-xx |
-+----------------------------------------------------------| -+----------------------------------------------------------|
Figure 1 Figure 1
15. Acknowledgments 17. Acknowledgments
The authors wish to thank Harald Alvestrand, Randell Jesup, Paul The authors wish to thank Harald Alvestrand, Randell Jesup, Paul
Kyzivat, Michael Tuexen for their comments and useful feedback. Kyzivat, Michael Tuexen for their comments and useful feedback.
16. Change Log 18. Change Log
[RFC EDITOR NOTE: Please remove this section when publishing] [RFC EDITOR NOTE: Please remove this section when publishing]
Changes from draft-ietf-mmusic-sctp-sdp-09
o 'DTLS/SCTP' split into 'UDP/DTLS/SCTP' and 'TCP/DTLS/SCTP'
o Procedures for realizing UDP/DTLS/SCTP- and TCP/DTLS/SCTP
transports added.
Changes from draft-ietf-mmusic-sctp-sdp-08 Changes from draft-ietf-mmusic-sctp-sdp-08
o Default SCTP port removed o Default SCTP port removed:
o - Usage of SDP sctp-port attribute mandatory o - Usage of SDP sctp-port attribute mandatory.
o SDP max-message-size attribute defined o SDP max-message-size attribute defined:
o - Attribute definition o - Attribute definition.
o - SDP Offer/Answer procedures o - SDP Offer/Answer procedures.
o Text about SDP direction attributes added o Text about SDP direction attributes added.
o Text about TLS role determination added o Text about TLS role determination added.
17. References 19. References
17.1. Normative References 19.1. Normative References
[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, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model [RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model
with Session Description Protocol (SDP)", RFC 3264, June with Session Description Protocol (SDP)", RFC 3264, June
2002. 2002.
[RFC4145] Yon, D. and G. Camarillo, "TCP-Based Media Transport in [RFC4145] Yon, D. and G. Camarillo, "TCP-Based Media Transport in
the Session Description Protocol (SDP)", RFC 4145, the Session Description Protocol (SDP)", RFC 4145,
September 2005. September 2005.
[RFC4289] Freed, N. and J. Klensin, "Multipurpose Internet Mail [RFC4289] Freed, N. and J. Klensin, "Multipurpose Internet Mail
Extensions (MIME) Part Four: Registration Procedures", BCP Extensions (MIME) Part Four: Registration Procedures", BCP
13, RFC 4289, December 2005. 13, RFC 4289, December 2005.
[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
Description Protocol", RFC 4566, July 2006. Description Protocol", RFC 4566, July 2006.
[RFC4571] Lazzaro, J., "Framing Real-time Transport Protocol (RTP)
and RTP Control Protocol (RTCP) Packets over Connection-
Oriented Transport", RFC 4571, July 2006.
[RFC4572] Lennox, J., "Connection-Oriented Media Transport over the [RFC4572] Lennox, J., "Connection-Oriented Media Transport over the
Transport Layer Security (TLS) Protocol in the Session Transport Layer Security (TLS) Protocol in the Session
Description Protocol (SDP)", RFC 4572, July 2006. Description Protocol (SDP)", RFC 4572, July 2006.
[RFC4960] Stewart, R., "Stream Control Transmission Protocol", RFC [RFC4960] Stewart, R., "Stream Control Transmission Protocol", RFC
4960, September 2007. 4960, September 2007.
[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, September Dynamic Address Reconfiguration", RFC 5061, September
skipping to change at page 17, line 43 skipping to change at page 18, line 29
[RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type [RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type
Specifications and Registration Procedures", BCP 13, RFC Specifications and Registration Procedures", BCP 13, RFC
6838, January 2013. 6838, January 2013.
[I-D.ietf-tsvwg-sctp-dtls-encaps] [I-D.ietf-tsvwg-sctp-dtls-encaps]
Tuexen, M., Stewart, R., Jesup, R., and S. Loreto, "DTLS Tuexen, M., Stewart, R., Jesup, R., and S. Loreto, "DTLS
Encapsulation of SCTP Packets", draft-ietf-tsvwg-sctp- Encapsulation of SCTP Packets", draft-ietf-tsvwg-sctp-
dtls-encaps-06 (work in progress), November 2014. dtls-encaps-06 (work in progress), November 2014.
17.2. Informative References 19.2. Informative References
[RFC5763] Fischl, J., Tschofenig, H., and E. Rescorla, "Framework [RFC5763] Fischl, J., Tschofenig, H., and E. Rescorla, "Framework
for Establishing a Secure Real-time Transport Protocol for Establishing a Secure Real-time Transport Protocol
(SRTP) Security Context Using Datagram Transport Layer (SRTP) Security Context Using Datagram Transport Layer
Security (DTLS)", RFC 5763, May 2010. Security (DTLS)", RFC 5763, May 2010.
[RFC5768] Rosenberg, J., "Indicating Support for Interactive [RFC5768] Rosenberg, J., "Indicating Support for Interactive
Connectivity Establishment (ICE) in the Session Initiation Connectivity Establishment (ICE) in the Session Initiation
Protocol (SIP)", RFC 5768, April 2010. Protocol (SIP)", RFC 5768, April 2010.
 End of changes. 92 change blocks. 
203 lines changed or deleted 242 lines changed or added

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