draft-ietf-tsvwg-addip-sctp-05.txt   draft-ietf-tsvwg-addip-sctp-06.txt 
Network Working Group R. R. Stewart Network Working Group R. Stewart
INTERNET-DRAFT M. A. Ramalho Internet-Draft M. Ramalho
Cisco Systems Expires: March 2, 2003 Cisco Systems, Inc.
Q. Xie Q. Xie
Motorola Motorola, Inc.
M. Tuexen M. Tuexen
Siemens AG Siemens AG
I. Rytina I. Rytina
M. Belinchon M. Belinchon
Ericsson Ericsson
P. Conrad P. Conrad
Temple University Temple University
September 2002
expires in six months May 12, 2002 Stream Control Transmission Protocol (SCTP) Dynamic Address
Reconfiguration
draft-ietf-tsvwg-addip-sctp-06.txt
Stream Control Transmission Protocol (SCTP) Status of this Memo
Dynamic Address Reconfiguration
<draft-ietf-tsvwg-addip-sctp-05.txt> This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
Status of This Memo Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
This document is an Internet-Draft and is in full conformance with Internet-Drafts are draft documents valid for a maximum of six months
all provisions of Section 10 of RFC 2026 [RFC2026]. Internet-Drafts and may be updated, replaced, or obsoleted by other documents at any
are working documents of the Internet Engineering Task Force (IETF), time. It is inappropriate to use Internet-Drafts as reference
its areas, and its working groups. Note that other groups may also material or to cite them other than as "work in progress."
distribute working documents as Internet-Drafts.
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at http://
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This Internet-Draft will expire on March 2, 2003.
Copyright Notice
Copyright (C) The Internet Society (2002). All Rights Reserved.
Abstract Abstract
This document describes extensions to the Stream Control This document describes extensions to the Stream Control Transmission
Transmission Protocol (SCTP) [RFC2960] that provides a method to Protocol (SCTP) [RFC2960] that provides a method to reconfigure IP
reconfigure IP address information on an existing association. address information on an existing association.
TABLE OF CONTENTS Table of Contents
1. Introduction............................................... 2
2. Conventions................................................ 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Additional Chunks and Parameters........................... 3 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1 New Chunk Types........................................... 3 3. Additional Chunks and Parameters . . . . . . . . . . . . . . 5
3.1.1 Address Configuration Change Chunk (ASCONF)............. 3 3.1 New Chunk Types . . . . . . . . . . . . . . . . . . . . . . 5
3.1.2 Address Configuration Acknowledgment Chunk 3.1.1 Address Configuration Change Chunk (ASCONF) . . . . . . . . 5
(ASCONF-ACK)............................................ 4 3.1.2 Address Configuration Acknowledgment Chunk (ASCONF-ACK) . . 6
3.2 New Parameter Types....................................... 5 3.2 New Parameter Types . . . . . . . . . . . . . . . . . . . . 7
3.2.1 Add IP Address.......................................... 6 3.2.1 Add IP Address . . . . . . . . . . . . . . . . . . . . . . . 8
3.2.2 Delete IP Address........................................ 6 3.3 Error Cause Indication . . . . . . . . . . . . . . . . . . . 10
3.2.3 Error Cause Indication................................... 7 3.4 Set Primary IP Address . . . . . . . . . . . . . . . . . . . 11
3.2.4 Set Primary IP Address................................... 8 3.5 Success Indication . . . . . . . . . . . . . . . . . . . . . 12
3.2.5 Success Indication....................................... 9 3.5.1 Adaptation Layer Indication . . . . . . . . . . . . . . . . 12
3.2.6 Adaption Layer Indication................................10 3.6 New Error Causes . . . . . . . . . . . . . . . . . . . . . . 13
3.3 New Error Causes...........................................10 3.6.1 Error Cause: Request to Delete Last Remaining IP Address . . 13
3.3.1 Error Cause: Request to Delete Last Remaining IP Address.10 3.6.2 Error Cause: Operation Refused Due to Resource Shortage . . 14
3.3.2 Error Cause: Operation Refused Due to Resource Shortage..11 3.6.3 Error Cause: Request to Delete Source IP Address . . . . . . 15
3.3.3 Error Cause: Request to Delete Source IP Address.........12 3.6.4 Error Cause: Association Aborted due to illegal ASCONF-ACK . 16
3.3.4 Error Cause: Association Aborted due to illegal 4. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 17
ASCONF-ACK...............................................12 4.1 ASCONF Chunk Procedures . . . . . . . . . . . . . . . . . . 17
4. Procedures..................................................12 4.1.1 Congestion Control of ASCONF Chunks . . . . . . . . . . . . 18
4.1 ASCONF Chunk Procedures....................................13 4.2 Upon reception of an ASCONF Chunk. . . . . . . . . . . . . . 19
4.1.1 Congestion Control of ASCONF Chunks......................14 4.3 General rules for address manipulation . . . . . . . . . . . 21
4.2 Upon reception of an ASCONF Chunk..........................15 4.3.1 A special case for OOTB ABORT chunks . . . . . . . . . . . . 25
4.3 General rules for address manipulation.....................17 4.3.2 A special case for changing an address. . . . . . . . . . . 25
4.3.1 A special case for OOTB ABORT chunks.....................19 4.4 Setting of the primary address . . . . . . . . . . . . . . . 26
4.3.2 A special case for changing an address...................20 5. Security Considerations . . . . . . . . . . . . . . . . . . 27
4.4 Setting of the primary address.............................20 6. IANA considerations . . . . . . . . . . . . . . . . . . . . 28
5. Abstract description of SCTP addressing.....................21 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 29
6. Security Considerations.....................................24 References . . . . . . . . . . . . . . . . . . . . . . . . . 30
7. IANA considerations.........................................24 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 30
8. Acknowledgments.............................................24 A. Abstract Address Handling . . . . . . . . . . . . . . . . . 33
9. Authors' Addresses..........................................24 A.1 General remarks . . . . . . . . . . . . . . . . . . . . . . 33
10.Normative References........................................25 A.2 Generalized endpoints . . . . . . . . . . . . . . . . . . . 33
A.3 Associations . . . . . . . . . . . . . . . . . . . . . . . . 34
A.4 Relationship with RFC 2960 . . . . . . . . . . . . . . . . . 35
A.5 Rules for address manipulation . . . . . . . . . . . . . . . 35
Full Copyright Statement . . . . . . . . . . . . . . . . . . 36
1. Introduction 1. Introduction
To extend the utility and application scenarios of SCTP, this To extend the utility and application scenarios of SCTP, this
document introduces optional extensions that provide SCTP with the document introduces optional extensions that provide SCTP with the
ability to: ability to:
1. reconfigure IP address information on an existing association. 1. reconfigure IP address information on an existing association.
2. set the remote primary path. 2. set the remote primary path.
3. exchange adaptation layer information during association setup. 3. exchange adaptation layer information during association setup.
These extensions enable SCTP to be utilized in the following These extensions enable SCTP to be utilized in the following
applications: applications:
1. For computational or networking platforms that allow 1. For computational or networking platforms that allow addition/
addition/removal of physical interface cards this feature can removal of physical interface cards this feature can provide a
provide a graceful method to add to the interfaces of an existing graceful method to add to the interfaces of an existing
association. For IPv6 this feature allows renumbering of existing association. For IPv6 this feature allows renumbering of
associations. existing associations.
2. This provides a method for an endpoint to request that its peer 2. This provides a method for an endpoint to request that its peer
set its primary destination address. This can be useful when an set its primary destination address. This can be useful when an
address is about to be deleted, or when an endpoint has some address is about to be deleted, or when an endpoint has some
predetermined knowledge about which is the preferred address to predetermined knowledge about which is the preferred address to
receive SCTP packets upon. receive SCTP packets upon.
3. This feature can be used to extend the usability of SCTP without 3. This feature can be used to extend the usability of SCTP without
modifying it by allowing endpoints to exchange some information modifying it by allowing endpoints to exchange some information
during association setup. during association setup.
2. Conventions 2. Conventions
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD, The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
SHOULD NOT, RECOMMENDED, NOT RECOMMENDED, MAY, and OPTIONAL, when SHOULD NOT, RECOMMENDED, NOT RECOMMENDED, MAY, and OPTIONAL, when
they appear in this document, are to be interpreted as described in they appear in this document, are to be interpreted as described in
RFC 2119 [RFC2119]. RFC2119 [2].
3. Additional Chunks and Parameters 3. Additional Chunks and Parameters
This section describes the addition of two new chunks and, eight This section describes the addition of two new chunks and, six new
new parameters to allow: parameters to allow:
- Dynamic addition of IP Addresses to an association. o Dynamic addition of IP Addresses to an association.
- Dynamic deletion of IP Addresses to an association.
- A request to set the primary address the peer will o Dynamic deletion of IP Addresses from an association.
use when sending to an endpoint.
o A request to set the primary address the peer will use when
sending to an endpoint.
Additionally, this section describes three new error causes that Additionally, this section describes three new error causes that
support these new chunks and parameters. support these new chunks and parameters.
3.1 New Chunk Types 3.1 New Chunk Types
This section defines two new chunk types that will be used to This section defines two new chunk types that will be used to
transfer the control information reliably. Table 1 illustrates the transfer the control information reliably. Table 1 illustrates the
two new chunk types. two new chunk types.
Chunk Type Chunk Name Chunk Type Chunk Name
-------------------------------------------------------------- --------------------------------------------------------------
0xC1 Address Configuration Change Chunk (ASCONF) 0xC1 Address Configuration Change Chunk (ASCONF)
0x80 Address Configuration Acknowledgment (ASCONF-ACK) 0x80 Address Configuration Acknowledgment (ASCONF-ACK)
Table 1: Address Configuration Chunks Table 1: Address Configuration Chunks
It should be noted that the ASCONF Chunk format requires the It should be noted that the ASCONF Chunk format requires the receiver
receiver to report to the sender if it does not understand the to report to the sender if it does not understand the ASCONF Chunk.
ASCONF Chunk. This is accomplished by setting the upper bits in the This is accomplished by setting the upper bits in the chunk type as
chunk type as described in [RFC2960] section 3.2. Note that the described in RFC2960 [5] section 3.2. Note that the upper two bits
upper two bits in the ASCONF Chunk are set to one. As defined in in the ASCONF Chunk are set to one. As defined in RFC2960 [5]
[RFC2960] section 3.2, setting these upper bits in this manner will section 3.2, setting these upper bits in this manner will cause the
cause the receiver that does not understand this chunk to skip the receiver that does not understand this chunk to skip the chunk and
chunk and continue processing, but report in an Operation Error continue processing, but report in an Operation Error Chunk using the
Chunk using the 'Unrecognized Chunk Type' cause of error. 'Unrecognized Chunk Type' cause of error.
3.1.1 Address Configuration Change Chunk (ASCONF) 3.1.1 Address Configuration Change Chunk (ASCONF)
This chunk is used to communicate to the remote endpoint one of the This chunk is used to communicate to the remote endpoint one of the
configuration change requests that MUST be acknowledged. The configuration change requests that MUST be acknowledged. The
information carried in the ASCONF Chunk uses the form of a information carried in the ASCONF Chunk uses the form of a Type-
Type-Length-Value (TLV), as described in "3.2.1 Length-Value (TLV), as described in "3.2.1 Optional/Variable-length
Optional/Variable-length Parameter Format" in [RFC2960], for Parameter Format" in RFC2960 [5], forall variable parameters.
all variable parameters.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 0xC1 | Chunk Flags | Chunk Length | | Type = 0xC1 | Chunk Flags | Chunk Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Number | | Serial Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Address Parameter | | Address Parameter |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 4, line 26 skipping to change at page 6, line 29
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ASCONF Parameter #N | | ASCONF Parameter #N |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Serial Number : 32 bits (unsigned integer) Serial Number : 32 bits (unsigned integer)
This value represents a Serial Number for the ASCONF Chunk. The This value represents a Serial Number for the ASCONF Chunk. The
valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). valid range of Serial Number is from 0 to 4294967295 (2**32 - 1).
Serial Numbers wrap back to 0 after reaching 4294967295. Serial Numbers wrap back to 0 after reaching 4294967295.
Reserved: 24 bits
Reserved, set to 0 by the sender and ignored by the
receiver.
Address Parameter : 8 or 20 bytes (depending on type) Address Parameter : 8 or 20 bytes (depending on type)
This field contains an address parameter, either IPv6 This field contains an address parameter, either IPv6 or IPv4, from
or IPv4, from RFC2960. The address is an address of the RFC2960 [5]. The address is an address of the sender of the ASCONF
sender of the ASCONF chunk, the address MUST be considered chunk, the address MUST be considered part of the association by the
part of the association by the peer endpoint (the receiver peer endpoint (the receiver of the ASCONF chunk). This field may be
of the ASCONF chunk). This field may be used by the receiver used by the receiver of the ASCONF to help in finding the
of the ASCONF to help in finding the association. This association. This parameter MUST be present in every ASCONF message
parameter MUST be present in every ASCONF message i.e. i.e. it is a mandatory TLV parameter.
it is a mandatory TLV parameter.
Note the host name address parameter is NOT allowed. Note the host name address parameter is NOT allowed and MUST be
ignored if received in any ASCONF message.
ASCONF Parameter: TLV format ASCONF Parameter: TLV format
Each Address configuration change is represented by a TLV Each Address configuration change is represented by a TLV parameter
parameter as defined in Section 3.2. One or more requests as defined in Section 3.2. One or more requests may be present in an
may be present in an ASCONF Chunk. ASCONF Chunk.
3.1.2 Address Configuration Acknowledgment Chunk (ASCONF-ACK) 3.1.2 Address Configuration Acknowledgment Chunk (ASCONF-ACK)
This chunk is used by the receiver of an ASCONF Chunk to acknowledge This chunk is used by the receiver of an ASCONF Chunk to acknowledge
the reception. It carries zero or more results for any ASCONF the reception. It carries zero or more results for any ASCONF
Parameters that were processed by the receiver. Parameters that were processed by the receiver.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 5, line 24 skipping to change at page 7, line 24
\ \ \ \
/ .... / / .... /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ASCONF Parameter Response#N | | ASCONF Parameter Response#N |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Serial Number : 32 bits (unsigned integer) Serial Number : 32 bits (unsigned integer)
This value represents the Serial Number for the received ASCONF Chunk This value represents the Serial Number for the received ASCONF Chunk
that is acknowledged by this chunk. This value is that is acknowledged by this chunk. This value is copied from the
copied from the received ASCONF Chunk. received ASCONF Chunk.
ASCONF Parameter Response : TLV format ASCONF Parameter Response : TLV format
The ASCONF Parameter Response is used in the ASCONF-ACK to report The ASCONF Parameter Response is used in the ASCONF-ACK to report
status of ASCONF processing. By default, if a responding endpoint status of ASCONF processing. By default, if a responding endpoint
does not include any Error Cause, a success is indicated. Thus a does not include any Error Cause, a success is indicated. Thus a
sender of an ASCONF-ACK MAY indicate complete success of all TLVs in sender of an ASCONF-ACK MAY indicate complete success of all TLVs in
an ASCONF by returning only the Chunk Type, Chunk Flags, Chunk Length an ASCONF by returning only the Chunk Type, Chunk Flags, Chunk Length
(set to 8) and the Serial Number. (set to 8) and the Serial Number.
3.2 New Parameter Types 3.2 New Parameter Types
The six new parameters added follow the format defined in section The six new parameters added follow the format defined in section
3.2.1 of [RFC2960]. Table 2 and 3 describes the parameters. 3.2.1 of RFC2960 [5]. Table 2 and 3 describes the parameters.
Address Configuration Parameters Parameter Type Address Configuration Parameters Parameter Type
------------------------------------------------- -------------------------------------------------
Add IP Address 0xC001 Add IP Address 0xC001
Delete IP Address 0xC002 Delete IP Address 0xC002
Set Primary Address 0xC004 Set Primary Address 0xC004
Adaption Layer Indication 0xC006 Adaption Layer Indication 0xC006
Table 2: Parameters used in ASCONF Parameter Table 2: Parameters used in ASCONF Parameter
Address Configuration Parameters Parameter Type Address Configuration Parameters Parameter Type
------------------------------------------------- -------------------------------------------------
Error Cause Indication 0xC003 Error Cause Indication 0xC003
Success report 0xC005 Success Indication 0xC005
Table 3: Parameters used in ASCONF Parameter Response Table 3: Parameters used in ASCONF Parameter Response
3.2.1 Add IP Address 3.2.1 Add IP Address
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 0xC001 | Length = Variable | | Type = 0xC001 | Length = Variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ASCONF-Request Correlation ID | | ASCONF-Request Correlation ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Address Parameter | | Address Parameter |
skipping to change at page 6, line 28 skipping to change at page 8, line 35
This is an opaque integer assigned by the sender to identify each This is an opaque integer assigned by the sender to identify each
request parameter. It is in host byte order and is only meaningful request parameter. It is in host byte order and is only meaningful
to the sender. The receiver of the ASCONF Chunk will copy this 32 to the sender. The receiver of the ASCONF Chunk will copy this 32
bit value into the ASCONF Response Correlation ID field of the bit value into the ASCONF Response Correlation ID field of the
ASCONF-ACK response parameter. The sender of the ASCONF can use this ASCONF-ACK response parameter. The sender of the ASCONF can use this
same value in the ASCONF-ACK to find which request the response is same value in the ASCONF-ACK to find which request the response is
for. for.
Address Parameter: TLV Address Parameter: TLV
This field contains an IPv4 or IPv6 address parameter as described This field contains an IPv4 or IPv6 address parameter as described in
in 3.3.2.1 of RFC2960. The complete TLV is wrapped within this 3.3.2.1 of RFC2960 [5]. The complete TLV is wrapped within this
parameter. It informs the receiver that the address specified is to parameter. It informs the receiver that the address specified is to
be added to the existing association. be added to the existing association.
An example TLV requesting that the IPv4 address 10.1.1.1 be An example TLV requesting that the IPv4 address 10.1.1.1 be added to
added to the association would look as follows: the association would look as follows:
+--------------------------------+ +--------------------------------+
| Type=0xC001 | Length = 16 | | Type=0xC001 | Length = 16 |
+--------------------------------+ +--------------------------------+
| C-ID = 0x01023474 | | C-ID = 0x01023474 |
+--------------------------------+ +--------------------------------+
| Type=5 | Length = 8 | | Type=5 | Length = 8 |
+----------------+---------------+ +----------------+---------------+
| Value=0x0a010101 | | Value=0x0a010101 |
+----------------+---------------+ +----------------+---------------+
Valid Chunk Appearance Valid Chunk Appearance
The Add IP Address parameter may only appear in the ASCONF Chunk The Add IP Address parameter may only appear in the ASCONF Chunk
type. type.
3.2.2 Delete IP Address
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type =0xC002 | Length = Variable | | Type =0xC002 | Length = Variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ASCONF-Request Correlation ID | | ASCONF-Request Correlation ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Address Parameter | | Address Parameter |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 7, line 19 skipping to change at page 9, line 43
request parameter. It is in host byte order and is only meaningful request parameter. It is in host byte order and is only meaningful
to the sender. The receiver of the ASCONF Chunk will copy this 32 to the sender. The receiver of the ASCONF Chunk will copy this 32
bit value into the ASCONF Response Correlation ID field of the bit value into the ASCONF Response Correlation ID field of the
ASCONF-ACK response parameter. The sender of the ASCONF can use this ASCONF-ACK response parameter. The sender of the ASCONF can use this
same value in the ASCONF-ACK to find which request the response is same value in the ASCONF-ACK to find which request the response is
for. for.
Address Parameter: TLV Address Parameter: TLV
This field contains an IPv4 or IPv6 address parameter as described in This field contains an IPv4 or IPv6 address parameter as described in
3.3.2.1 of [RFC2960]. The complete TLV is wrapped within this 3.3.2.1 of RFC2960 [5]. The complete TLV is wrapped within this
parameter. It informs the receiver that the address specified is to parameter. It informs the receiver that the address specified is to
be removed from the existing association. be removed from the existing association.
An example TLV deleting the IPv4 address 10.1.1.1 from an existing An example TLV deleting the IPv4 address 10.1.1.1 from an existing
association would look as follows: association would look as follows:
+--------------------------------+ +--------------------------------+
| Type=0xC002 | Length = 16 | | Type=0xC002 | Length = 16 |
+--------------------------------+ +--------------------------------+
| C-ID = 0x01023476 | | C-ID = 0x01023476 |
skipping to change at page 7, line 41 skipping to change at page 10, line 20
| Type=5 | Length = 8 | | Type=5 | Length = 8 |
+----------------+---------------+ +----------------+---------------+
| Value=0x0a010101 | | Value=0x0a010101 |
+----------------+---------------+ +----------------+---------------+
Valid Chunk Appearance Valid Chunk Appearance
The Delete IP Address parameter may only appear in the ASCONF Chunk The Delete IP Address parameter may only appear in the ASCONF Chunk
type. type.
3.2.3 Error Cause Indication 3.3 Error Cause Indication
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 0xC003 | Length = Variable | | Type = 0xC003 | Length = Variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ASCONF-Response Correlation ID | | ASCONF-Response Correlation ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Cause(s) or Return Info on Success | | Error Cause(s) or Return Info on Success |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 0xC003 | Length = Variable | | Type = 0xC003 | Length = Variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ASCONF-Response Correlation ID | | ASCONF-Response Correlation ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Cause(s) or Return Info on Success | | Error Cause(s) or Return Info on Success |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
ASCONF-Response Correlation ID: 32 bits ASCONF-Response Correlation ID: 32 bits
This is an opaque integer assigned by the sender to identify each This is an opaque integer assigned by the sender to identify each
request parameter. The receiver of the ASCONF Chunk will copy this 32 request parameter. The receiver of the ASCONF Chunk will copy this
bit value from the ASCONF-Request Correlation ID into the ASCONF 32 bit value from the ASCONF-Request Correlation ID into the ASCONF
Response Correlation ID field so the peer can easily correlate the Response Correlation ID field so the peer can easily correlate the
request to this response. request to this response.
Error Cause(s): TLV(s) Error Cause(s): TLV(s)
When reporting an error this response parameter is used to wrap When reporting an error this response parameter is used to wrap one
one or more standard error causes normally found within an SCTP or more standard error causes normally found within an SCTP
Operational Error or SCTP Abort (as defined in [RFC2960]). The Operational Error or SCTP Abort (as defined in RFC2960 [5]). The
Error Cause(s) follow the format defined in section 3.3.10 of Error Cause(s) follow the format defined in section 3.3.10 of RFC2960
[RFC2960]. [5].
Valid Chunk Appearance Valid Chunk Appearance
The Error Cause Indication parameter may only appear in the The Error Cause Indication parameter may only appear in the ASCONF-
ASCONF-ACK chunk type. ACK chunk type.
3.2.4 Set Primary IP Address 3.4 Set Primary IP Address
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type =0xC004 | Length = Variable | | Type =0xC004 | Length = Variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ASCONF-Request Correlation ID | | ASCONF-Request Correlation ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Address Parameter | | Address Parameter |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 8, line 48 skipping to change at page 11, line 30
request parameter. It is in host byte order and is only meaningful request parameter. It is in host byte order and is only meaningful
to the sender. The receiver of the ASCONF Chunk will copy this 32 to the sender. The receiver of the ASCONF Chunk will copy this 32
bit value into the ASCONF Response Correlation ID field of the bit value into the ASCONF Response Correlation ID field of the
ASCONF-ACK response parameter. The sender of the ASCONF can use this ASCONF-ACK response parameter. The sender of the ASCONF can use this
same value in the ASCONF-ACK to find which request the response is same value in the ASCONF-ACK to find which request the response is
for. for.
Address Parameter: TLV Address Parameter: TLV
This field contains an IPv4 or IPv6 address parameter as described in This field contains an IPv4 or IPv6 address parameter as described in
3.3.2.1 of [RFC2960]. The complete TLV is wrapped within this 3.3.2.1 of RFC2960 [5]. The complete TLV is wrapped within this
parameter. It requests the receiver to mark the specified address parameter. It requests the receiver to mark the specified address as
as the primary address to send data to (see section 5.1.2 of the primary address to send data to (see section 5.1.2 of RFC2960
[RFC2960]). The receiver MAY mark this as its primary upon [5]). The receiver MAY mark this as its primary upon receiving this
receiving this request. request.
An example TLV requesting that the IPv4 address 10.1.1.1 be made the An example TLV requesting that the IPv4 address 10.1.1.1 be made the
primary destination address would look as follows: primary destination address would look as follows:
+--------------------------------+ +--------------------------------+
| Type=0xC004 | Length = 18 | | Type=0xC004 | Length = 18 |
+--------------------------------+ +--------------------------------+
| C-ID = 0x01023479 | | C-ID = 0x01023479 |
+--------------------------------+ +--------------------------------+
| Type=5 | Length = 8 | | Type=5 | Length = 8 |
+----------------+---------------+ +----------------+---------------+
| Value=0x0a010101 | | Value=0x0a010101 |
+----------------+---------------+ +----------------+---------------+
Valid Chunk Appearance Valid Chunk Appearance
The Set Primary IP Address parameter may appear in the ASCONF Chunk, The Set Primary IP Address parameter may appear in the ASCONF Chunk,
the INIT, or the INIT-ACK chunk type. The inclusion of this parameter the INIT, or the INIT-ACK chunk type. The inclusion of this
in the INIT or INIT-ACK can be used to indicate an initial preference parameter in the INIT or INIT-ACK can be used to indicate an initial
of primary address. preference of primary address.
3.2.5 Success Indication 3.5 Success Indication
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 0xC005 | Length = 8 | | Type = 0xC005 | Length = 8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ASCONF-Response Correlation ID | | ASCONF-Response Correlation ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
By default if a responding endpoint does not report an error for any By default if a responding endpoint does not report an error for any
skipping to change at page 9, line 45 skipping to change at page 12, line 30
returning only the Chunk Type, Chunk Flags, Chunk Length (set to 8) returning only the Chunk Type, Chunk Flags, Chunk Length (set to 8)
and the Serial Number. and the Serial Number.
The responding endpoint MAY also choose to explicitly report a The responding endpoint MAY also choose to explicitly report a
success for a requested TLV, by returning a success report ASCONF success for a requested TLV, by returning a success report ASCONF
Parameter Response. Parameter Response.
ASCONF-Response Correlation ID: 32 bits ASCONF-Response Correlation ID: 32 bits
This is an opaque integer assigned by the sender to identify each This is an opaque integer assigned by the sender to identify each
request parameter. The receiver of the ASCONF Chunk will copy this 32 request parameter. The receiver of the ASCONF Chunk will copy this
bit value from the ASCONF-Request Correlation ID into the ASCONF 32 bit value from the ASCONF-Request Correlation ID into the ASCONF
Response Correlation ID field so the peer can easily correlate the Response Correlation ID field so the peer can easily correlate the
request to this response. request to this response.
Valid Chunk Appearance Valid Chunk Appearance
The Success Indication parameter may only appear in the ASCONF-ACK The Success Indication parameter may only appear in the ASCONF-ACK
chunk type. chunk type.
3.2.6 Adaption Layer Indication 3.5.1 Adaptation Layer Indication
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type =0xC006 | Length = Variable | | Type =0xC006 | Length = Variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved Bit Fields | | Adaption Code point |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This parameter is specified for the communication of peer upper This parameter is specified for the communication of peer upper layer
layer protocols. It is envisioned to be used for flow control protocols. It is envisioned to be used for flow control and other
and other adaption layers that require an indication to be adaptation layers that require an indication to be carried in the
carried in the INIT and INIT-ACK. Each adaption layer that INIT and INIT-ACK. Each adaptation layer that is defined that wishes
is defined that wishes to use this parameter MUST specify to use this parameter MUST specify a an adaption code point in an
a bit in the reserved bit field in an appropriate RFC. This appropriate RFC defining its use and meaning. This parameter SHOULD
parameter SHOULD NOT be examined by the receiving SCTP NOT be examined by the receiving SCTP implementation and should be
implementation and should be passed opaquely to the upper passed opaquely to the upper layer protocol.
layer protocol.
Valid Chunk Appearance Valid Chunk Appearance
The Adaption Layer Indication parameter may appear in INIT or The Adaptation Layer Indication parameter may appear in INIT or INIT-
INIT-ACK chunk and SHOULD be passed to the receivers upper layer ACK chunk and SHOULD be passed to the receivers upper layer protocol.
protocol.
3.3 New Error Causes 3.6 New Error Causes
Four new Error Causes are added to the SCTP Operational Errors, Four new Error Causes are added to the SCTP Operational Errors,
primarily for use in the ASCONF-ACK chunk. primarily for use in the ASCONF-ACK chunk.
Cause Code Cause Code
Value Cause Code Value Cause Code
--------- ---------------- --------- ----------------
0x000B Request to Delete Last Remaining IP Address. 0x0100 Request to Delete Last Remaining IP Address.
0x000C Operation Refused Due to Resource Shortage. 0x0101 Operation Refused Due to Resource Shortage.
0x000D Request to Delete Source IP Address. 0x0102 Request to Delete Source IP Address.
0x000E Association Aborted due to illegal ASCONF-ACK 0x0103 Association Aborted due to illegal ASCONF-ACK
Table 3: New Error Causes Table 4: New Error Causes
3.3.1 Error Cause: Request to Delete Last Remaining IP Address 3.6.1 Error Cause: Request to Delete Last Remaining IP Address
Cause of error Cause of error
---------------
Request to Delete Last Remaining IP address: The receiver of this Request to Delete Last Remaining IP address: The receiver of this
error sent a request to delete the last IP address from its error sent a request to delete the last IP address from its
association with its peer. This error indicates that the request is association with its peer. This error indicates that the request is
rejected. rejected.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cause Code=0x000B | Cause Length=Variable | | Cause Code=0x0100 | Cause Length=Variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ TLV-Copied-From-ASCONF / \ TLV-Copied-From-ASCONF /
/ \ / \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
An example of a failed delete in an Error Cause TLV would look as An example of a failed delete in an Error Cause TLV would look as
follows in the response ASCONF-ACK message: follows in the response ASCONF-ACK message:
+--------------------------------+ +--------------------------------+
| Type = 0xC003 | Length = 24 | | Type = 0xC003 | Length = 24 |
+--------------------------------+ +--------------------------------+
| C-ID = 0x01023476 | | C-ID = 0x01023476 |
+--------------------------------+ +--------------------------------+
| Cause=0x000B | Length = 16 | | Cause=0x0100 | Length = 16 |
+----------------+---------------+ +----------------+---------------+
| Type= 0xC002 | Length = 12 | | Type= 0xC002 | Length = 12 |
+----------------+---------------+ +----------------+---------------+
| Type=0x0005 | Length = 8 | | Type=0x0005 | Length = 8 |
+----------------+---------------+ +----------------+---------------+
| Value=0x0A010101 | | Value=0x0A010101 |
+----------------+---------------+ +----------------+---------------+
3.3.2 Error Cause: Operation Refused Due to Resource Shortage 3.6.2 Error Cause: Operation Refused Due to Resource Shortage
Cause of error Cause of error
---------------
This error cause is used to report a failure by the receiver to This error cause is used to report a failure by the receiver to
perform the requested operation due to a lack of resources. The perform the requested operation due to a lack of resources. The
entire TLV that is refused is copied from the ASCONF into the entire TLV that is refused is copied from the ASCONF into the error
error cause. cause.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cause Code=0x000C | Cause Length=Variable | | Cause Code=0x0101 | Cause Length=Variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ TLV-Copied-From-ASCONF / \ TLV-Copied-From-ASCONF /
/ \ / \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
An example of a failed addition in an Error Cause TLV would look as An example of a failed addition in an Error Cause TLV would look as
follows in the response ASCONF-ACK message: follows in the response ASCONF-ACK message:
+--------------------------------+ +--------------------------------+
| Type = 0xC003 | Length = 24 | | Type = 0xC003 | Length = 24 |
+--------------------------------+ +--------------------------------+
| C-ID = 0x01023474 | | C-ID = 0x01023474 |
+--------------------------------+ +--------------------------------+
| Cause=0x000C | Length = 16 | | Cause=0x0101 | Length = 16 |
+----------------+---------------+ +----------------+---------------+
| Type=0xC001 | Length = 12 | | Type=0xC001 | Length = 12 |
+--------------------------------+ +--------------------------------+
| Type=0x0005 | Length = 8 | | Type=0x0005 | Length = 8 |
+----------------+---------------+ +----------------+---------------+
| Value=0x0A010101 | | Value=0x0A010101 |
+----------------+---------------+ +----------------+---------------+
3.3.3 Error Cause: Request to Delete Source IP Address 3.6.3 Error Cause: Request to Delete Source IP Address
Cause of error Cause of error
---------------
Request to Delete Source IP Address: The receiver of this error sent Request to Delete Source IP Address: The receiver of this error sent
a request to delete the source IP address of the ASCONF a request to delete the source IP address of the ASCONF message.
message. This error indicates that the request is rejected. This error indicates that the request is rejected.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cause Code=0x000D | Cause Length=Variable | | Cause Code=0x0102 | Cause Length=Variable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ TLV-Copied-From-ASCONF / \ TLV-Copied-From-ASCONF /
/ \ / \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
An example of a failed delete in an Error Cause TLV would look as An example of a failed delete in an Error Cause TLV would look as
follows in the response ASCONF-ACK message: follows in the response ASCONF-ACK message:
+--------------------------------+ +--------------------------------+
| Type = 0xC003 | Length = 24 | | Type = 0xC003 | Length = 24 |
+--------------------------------+ +--------------------------------+
| C-ID = 0x01023476 | | C-ID = 0x01023476 |
+--------------------------------+ +--------------------------------+
| Cause=0x000D | Length = 16 | | Cause=0x0102 | Length = 16 |
+----------------+---------------+ +----------------+---------------+
| Type=0xC002 | Length = 12 | | Type=0xC002 | Length = 12 |
+----------------+---------------+ +----------------+---------------+
| Type=0x0005 | Length = 8 | | Type=0x0005 | Length = 8 |
+----------------+---------------+ +----------------+---------------+
| Value=0x0A010101 | | Value=0x0A010101 |
+----------------+---------------+ +----------------+---------------+
IMPLEMENTATION NOTE: It is unlikely that an endpoint would source a
packet from the address being deleted, unless the endpoint does not
do proper source address selection.
IMPLEMENTATION NOTE: It is unlikely that an endpoint would source 3.6.4 Error Cause: Association Aborted due to illegal ASCONF-ACK
a packet from the address being deleted, unless the endpoint
does not do proper source address selection.
3.3.4 Error Cause: Association Aborted due to illegal ASCONF-ACK
This error is to be included in an ABORT that is generated due This error is to be included in an ABORT that is generated due to the
to the reception of an ASCONF-ACK that was not expected but reception of an ASCONF-ACK that was not expected but is larger than
would have been the next correct ASCONF-ACK (see section the current sequence number (see Section 4.3 Rule D0 ). Note that a
4.3 rule D0). sequence number is larger than the last acked sequence number if it
is either the next sequence or no more than 2^^31 greater than the
current sequence number.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cause Code=0x000E | Cause Length=4 | | Cause Code=0x0103 | Cause Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4. Procedures 4. Procedures
This section will lay out the specific procedures for address This section will lay out the specific procedures for address
configuration change chunk type and its processing. configuration change chunk type and its processing.
4.1 ASCONF Chunk Procedures 4.1 ASCONF Chunk Procedures
When an endpoint has an ASCONF signaled change to be sent to the When an endpoint has an ASCONF signaled change to be sent to the
remote endpoint it should do the following: remote endpoint it should do the following:
A1) Create an ASCONF Chunk as defined in section 3.1.1. The chunk A1) Create an ASCONF Chunk as defined in Section 3.1.1. The chunk
should contain all of the TLV(s) of information necessary to be should contain all of the TLV(s) of information necessary to be
sent to the remote endpoint, and unique correlation identities for sent to the remote endpoint, and unique correlation identities for
each request. each request.
A2) A serial number should be assigned to the Chunk. The serial A2) A serial number should be assigned to the Chunk. The serial
number should be a monotonically increasing number. All serial number should be a monotonically increasing number. The serial
numbers are defined to be initialized at the start of the number SHOULD be initialized at the start of the association to
association to the same value as the Initial TSN and are incremented the same value as the Initial TSN and every time a new ASCONF
by one. chunk is created it is incremented by one after assigning the
serial number to the newly created chunk .
A3) If no ASCONF Chunk is outstanding (un-acknowledged) with the A3) If no ASCONF Chunk is outstanding (un-acknowledged) with the
remote peer, send the chunk. remote peer, send the chunk.
A4) Start a T-4 RTO timer, using the RTO value of the selected A4) Start a T-4 RTO timer, using the RTO value of the selected
destination address (normally the primary path; see [RFC2960] section destination address (normally the primary path; see RFC2960 [5]
6.4 for details). section 6.4 for details).
A5) When the ASCONF-ACK that acknowledges the serial number last A5) When the ASCONF-ACK that acknowledges the serial number last sent
sent arrives, stop the T-4 RTO timer, and clear the appropriate arrives, stop the T-4 RTO timer, and clear the appropriate
association and destination error counters as defined in [RFC2960] association and destination error counters as defined in RFC2960
section 8.1 and 8.2. [5] section 8.1 and 8.2.
A6) Process all of the TLVs within the ASCONF-ACK to find out A6) Process all of the TLVs within the ASCONF-ACK to find out
particular status information returned to the various requests that particular status information returned to the various requests
were sent. Use the Correlation IDs to correlate the request and the that were sent. Use the Correlation IDs to correlate the request
responses. and the responses.
A7) If an error response is received for a TLV parameter, A7) If an error response is received for a TLV parameter, all TLVs
all TLVs with no response before the failed TLV are considered with no response before the failed TLV are considered successful
successful if not reported. All TLVs after the failed response are if not reported. All TLVs after the failed response are
considered unsuccessful unless a specific success indication is considered unsuccessful unless a specific success indication is
present for the parameter. present for the parameter.
A8) If there is no response(s) to specific TLV parameter(s), and no A8) If there is no response(s) to specific TLV parameter(s), and no
failures are indicated, then all request(s) are considered failures are indicated, then all request(s) are considered
successful. successful.
A9) If the peer responds to a ASCONF with an unrecognized chunk type, A9) If the peer responds to an ASCONF with an ERROR chunk reporting
the sender of the ASCONF MUST NOT send any further ASCONF chunks and that it did not recognized the ASCONF chunk type, the sender of
MUST stop its T-4 timer. the ASCONF MUST NOT send any further ASCONF chunks and MUST stop
its T-4 timer.
If the T-4 RTO timer expires the endpoint should do the following: If the T-4 RTO timer expires the endpoint should do the following:
B1) Increment the error counters and perform path failure detection B1) Increment the error counters and perform path failure detection
on the appropriate destination address as defined in [RFC2960] on the appropriate destination address as defined in RFC2960 [5]
section 8.1 and 8.2. section 8.1 and 8.2.
B2) Increment the association error counters and perform endpoint B2) Increment the association error counters and perform endpoint
failure detection on the association as defined in [RFC2960] section failure detection on the association as defined in RFC2960 [5]
8.1 and 8.2. section 8.1 and 8.2.
B3) Back-off the destination address RTO value to which the ASCONF B3) Back-off the destination address RTO value to which the ASCONF
chunk was sent by doubling the RTO timer value. chunk was sent by doubling the RTO timer value.
Note: The RTO value is used in the setting of all timer types Note: The RTO value is used in the setting of all timer types for
for SCTP. Each destination address has a single RTO estimate. SCTP. Each destination address has a single RTO estimate.
B4) Re-transmit the ASCONF Chunk last sent and if possible choose an B4) Re-transmit the ASCONF Chunk last sent and if possible choose an
alternate destination address (please refer to [RFC2960] section alternate destination address (please refer to RFC2960 [5] section
6.4.1). An endpoint MUST NOT add new parameters to this chunk, it 6.4.1). An endpoint MUST NOT add new parameters to this chunk, it
MUST be the same (including its serial number) as the last ASCONF MUST be the same (including its serial number) as the last ASCONF
sent. sent.
B5) Restart the T-4 RTO timer. Note that if a different destination is B5) Restart the T-4 RTO timer. Note that if a different destination
selected, then the RTO used will be that of the new destination is selected, then the RTO used will be that of the new destination
address. address.
Note: the total number of re-transmissions is limited by B2 Note: the total number of re-transmissions is limited by B2 above.
above. If the maximum is reached, the association will fail and enter If the maximum is reached, the association will fail and enter into
a CLOSED state (see [RFC2960] section 6.4.1 for details). the CLOSED state (see RFC2960 [5] section 6.4.1 for details).
4.1.1 Congestion Control of ASCONF Chunks 4.1.1 Congestion Control of ASCONF Chunks
In defining the ASCONF Chunk transfer procedures, it is essential In defining the ASCONF Chunk transfer procedures, it is essential
that these transfers MUST NOT cause congestion within the network. that these transfers MUST NOT cause congestion within the network.
To achieve this, we place these restrictions on the transfer of To achieve this, we place these restrictions on the transfer of
ASCONF Chunks: ASCONF Chunks:
R1) One and only one ASCONF Chunk MAY be in transit and R1) One and only one ASCONF Chunk MAY be in transit and
unacknowledged at any one time. If a sender, after sending an ASCONF unacknowledged at any one time. If a sender, after sending an
chunk, decides it needs to transfer another ASCONF Chunk, it MUST ASCONF chunk, decides it needs to transfer another ASCONF Chunk,
wait until the ASCONF-ACK Chunk returns from the previous ASCONF it MUST wait until the ASCONF-ACK Chunk returns from the previous
Chunk before sending a subsequent ASCONF. Note this restriction ASCONF Chunk before sending a subsequent ASCONF. Note this
binds each side, so at any time two ASCONF may be in-transit on any restriction binds each side, so at any time two ASCONF may be in-
given association (one sent from each endpoint). transit on any given association (one sent from each endpoint).
R2) An ASCONF may be bundled with any other chunk type (except other R2) An ASCONF may be bundled with any other chunk type (except other
ASCONF Chunks). ASCONF Chunks).
R3) An ASCONF-ACK may be bundled with any other chunk type except R3) An ASCONF-ACK may be bundled with any other chunk type except
other ASCONF-ACKs. other ASCONF-ACKs.
R4) Both ASCONF and ASCONF-ACK chunks MUST NOT be sent in any SCTP R4) Both ASCONF and ASCONF-ACK chunks MUST NOT be sent in any SCTP
state except ESTABLISHED. state except ESTABLISHED.
R5) An ASCONF MUST NOT be larger than the path MTU of the destination. R5) An ASCONF MUST NOT be larger than the path MTU of the
destination.
R6) An ASCONF-ACK SHOULD not be larger than the path MTU. In some R6) An ASCONF-ACK SHOULD not be larger than the path MTU. In some
circumstances an ASCONF-ACK may exceed the path MTU and in such circumstances an ASCONF-ACK may exceed the path MTU and in such a
a case IP fragmentation must be used. case IP fragmentation should be used to transmit the chunk.
If the sender of an ASCONF Chunk receives an Operational Error If the sender of an ASCONF Chunk receives an Operational Error
indicating that the ASCONF chunk type is not understood, then the indicating that the ASCONF chunk type is not understood, then the
sender MUST not send subsequent ASCONF Chunks to the peer. The sender MUST NOT send subsequent ASCONF Chunks to the peer. The
endpoint should also inform the upper layer application that the endpoint should also inform the upper layer application that the peer
peer endpoint does not support any of the extensions detailed in this endpoint does not support any of the extensions detailed in this
document. document.
4.2 Upon reception of an ASCONF Chunk. 4.2 Upon reception of an ASCONF Chunk.
When an endpoint receives an ASCONF Chunk from the remote peer When an endpoint receives an ASCONF Chunk from the remote peer
special procedures MAY be needed to identify the association special procedures MAY be needed to identify the association the
the ASCONF Chunk is associated with. To properly find the ASCONF Chunk is associated with. To properly find the association
association the following procedures should be followed: the following procedures should be followed:
L1) Use the source address and port number of the sender to L1) Use the source address and port number of the sender to attempt
attempt to identify the association (i.e. use the same method to identify the association (i.e. use the same method defined in
defined in [RFC2960] used for all other SCTP chunks ). If found RFC2960 [5] used for all other SCTP chunks). If found proceed to
proceed to rule L4. rule L4.
L2) If the association is not found, use the address found L2) If the association is not found, use the address found in the
in the Address Bytes field combined with the port number Address Parameter TLV combined with the port number found in the
found in the SCTP common header. If found proceed to rule SCTP common header. If found proceed to rule L4.
L4.
L3) If neither L1 or L2 locates the association, treat L3) If neither L1 or L2 locates the association, treat the chunk as
the chunk as an Out Of The Blue chunk as defined in an Out Of The Blue chunk as defined in RFC2960 [5].
[RFC2960].
L4) Follow the normal rules to validate the SCTP verification L4) Follow the normal rules to validate the SCTP verification tag
tag found in [RFC2960]. found in RFC2960 [5].
After identification and verification of the association, After identification and verification of the association, the
the following should be performed to properly process the ASCONF Chunk: following should be performed to properly process the ASCONF Chunk:
C1) Compare the value of the serial number to the value the endpoint C1) Compare the value of the serial number to the value the endpoint
stored in a new association variable 'Peer-Serial-Number'. This stored in a new association variable 'Peer-Serial-Number'. This
value MUST be initialized to the Initial TSN value minus 1. value MUST be initialized to the Initial TSN value minus 1.
C2) If the value found in the serial number is equal to the C2) If the value found in the serial number is equal to the ('Peer-
('Peer-Serial-Number' + 1), the endpoint MUST: Serial-Number' + 1), the endpoint MUST:
V1) Process the TLVs contained within the Chunk performing the V1) Process the TLVs contained within the Chunk performing the
appropriate actions as indicated by each TLV type. The TLVs MUST appropriate actions as indicated by each TLV type. The TLVs
be processed in order within the Chunk. For example, if the sender MUST be processed in order within the Chunk. For example, if
puts 3 TLVs in one chunk, the first TLV (the one closest to the the sender puts 3 TLVs in one chunk, the first TLV (the one
Chunk Header) in the Chunk MUST be processed first. The next TLV in closest to the Chunk Header) in the Chunk MUST be processed
the chunk (the middle one) MUST be processed second and finally the first. The next TLV in the chunk (the middle one) MUST be
last TLV in the Chunk MUST be processed last. processed second and finally the last TLV in the Chunk MUST be
processed last.
V2) In processing the chunk, the receiver should build a response V2) In processing the chunk, the receiver should build a response
message with the appropriate error TLVs, as specified in the message with the appropriate error TLVs, as specified in the
Parameter type bits for any ASCONF Parameter it does not understand. Parameter type bits for any ASCONF Parameter it does not
To indicate an unrecognized parameter, cause type 8 as defined understand. To indicate an unrecognized parameter, cause type
in the INIT-ACK in 3.3.10.8 of [RFC2960] should be used. The 8 as defined in the ERROR in 3.3.10.8 of RFC2960 [5] should be
endpoint may also use the response to carry rejections for other used. The endpoint may also use the response to carry
reasons such as resource shortages etc using the Error Cause TLV and rejections for other reasons such as resource shortages etc,
an appropriate error condition. using the Error Cause TLV and an appropriate error condition.
Note: a positive response is implied if no error is indicated by the Note: a positive response is implied if no error is indicated
sender. by the sender.
V3) All error responses MUST copy the ASCONF-Request Correlation ID V3) All responses MUST copy the ASCONF-Request Correlation ID
field received in the ASCONF, from the TLV being responded to, into field received in the ASCONF parameter, from the TLV being
the ASCONF-Request Correlation ID field. The ASCONF-Request responded to, into the ASCONF-Request Correlation ID field in
Correlation ID always precedes the request TLV. Note that a the response parameter.
TLV sent in an ASCONF-ACK MUST be accompanied by a Correlation ID
and a Correlation ID MUST NOT be sent without a TLV i.e. the two
are atomic.
V4) After processing the entire Chunk, it MUST send all TLVs for V4) After processing the entire Chunk, the receiver of the ASCONF
both unrecognized parameters and any other status TLVs inside the MUST send all TLVs for both unrecognized parameters and any
ASCONF-ACK chunk that acknowledges the arrival and processing of the other status TLVs inside the ASCONF-ACK chunk that acknowledges
ASCONF Chunk. the arrival and processing of the ASCONF Chunk.
V5) Update the 'Peer-Serial-Number' to the value found in the serial V5) Update the 'Peer-Serial-Number' to the value found in the
number field. serial number field.
C3) If the value found in the serial number is equal to the value C3) If the value found in the serial number is equal to the value
stored in the 'Peer-Serial-Number', the endpoint should: stored in the 'Peer-Serial-Number', the endpoint should:
X1) Parse the ASCONF Chunk TLVs but the endpoint MUST NOT take any X1) Parse the ASCONF Chunk TLVs but the endpoint MUST NOT take any
action on the TLVs parsed (since it has already performed these action on the TLVs parsed (since it has already performed these
actions). actions).
X2) Build a response message with the appropriate response TLVs X2) Build a response message with the appropriate response TLVs as
as specified in the ASCONF Parameter type bits, for any specified in the ASCONF Parameter type bits, for any parameter
parameter it does not understand or could not process. it does not understand or could not process.
X3) After parsing the entire Chunk, it MUST send any response X3) After parsing the entire Chunk, it MUST send any response TLV
TLV errors and status with an ASCONF-ACK chunk acknowledging the errors and status with an ASCONF-ACK chunk acknowledging the
arrival and processing of the ASCONF Chunk. arrival and processing of the ASCONF Chunk.
X4) The endpoint MUST NOT update its 'Peer-Serial-Number'. X4) The endpoint MUST NOT update its 'Peer-Serial-Number'.
Note: the response to the retransmitted ASCONF MUST be the same Note: the response to the retransmitted ASCONF MUST be the same as
as the original response. This MAY mean an implementation must the original response. This MAY mean an implementation must keep
keep state in order to respond with the same exact answer state in order to respond with the same exact answer (including
(including resource considerations that may have made the resource considerations that may have made the implementation
implementation refuse a request). refuse a request).
IMPLEMENTATION NOTE: As an optimization a receiver may wish to save IMPLEMENTATION NOTE: As an optimization a receiver may wish to
the last ASCONF-ACK for some predetermined period of time and save the last ASCONF-ACK for some predetermined period of time and
instead of re-processing the ASCONF (with the same serial number) it instead of re-processing the ASCONF (with the same serial number)
may just re-transmit the ASCONF-ACK. It may wish to use the arrival it may just re-transmit the ASCONF-ACK. It may wish to use the
of a new serial number to discard the previously saved ASCONF-ACK or arrival of a new serial number to discard the previously saved
any other means it may choose to expire the saved ASCONF-ACK. ASCONF-ACK or any other means it may choose to expire the saved
ASCONF-ACK.
C4) Otherwise, the ASCONF Chunk is discarded since it must be either C4) Otherwise, the ASCONF Chunk is discarded since it must be either
a stale packet or from an attacker. A receiver of such a packet MAY a stale packet or from an attacker. A receiver of such a packet
log the event for security purposes. MAY log the event for security purposes.
C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent back to the C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent back to the
source address contained in the IP header of the ASCONF being source address contained in the IP header of the ASCONF being
responded to. responded to.
4.3 General rules for address manipulation 4.3 General rules for address manipulation
When building TLV parameters for the ASCONF Chunk that When building TLV parameters for the ASCONF Chunk that will add or
will add or delete IP addresses the following rules should be delete IP addresses the following rules should be applied:
applied:
D0) If an endpoint receives an ASCONF-ACK but no ASCONF chunk D0) If an endpoint receives an ASCONF-ACK that is greater than or
is outstanding the endpoint MUST ABORT the association. equal to the next sequence number to be used but no ASCONF chunk
is outstanding the endpoint MUST ABORT the association. Note that
a sequence number is greater than if it is no more than 2^^31-1
larger than the current sequence number (using serial arithmetic).
D1) When adding an IP address to an association, the IP address is D1) When adding an IP address to an association, the IP address is
NOT considered fully added to the association until the ASCONF-ACK NOT considered fully added to the association until the ASCONF-ACK
arrives. This means that until such time as the ASCONF containing arrives. This means that until such time as the ASCONF containing
the add is acknowledged the sender MUST NOT use the new IP address the add is acknowledged the sender MUST NOT use the new IP address
as a source for ANY SCTP packet except on carrying an ASCONF chunk. as a source for ANY SCTP packet except on carrying an ASCONF
The receiver of the add IP address request may use the chunk. The receiver of the add IP address request may use the
address as a destination immediately. address as a destination immediately.
D2) After the ASCONF-ACK of an IP address add arrives, the D2) After the ASCONF-ACK of an IP address add arrives, the endpoint
endpoint MAY begin using the added IP address as a source MAY begin using the added IP address as a source address for any
address for any type of SCTP chunk. type of SCTP chunk.
D3a) If an endpoint receives an Error Cause TLV indicating that the D3a) If an endpoint receives an Error Cause TLV indicating that the
IP address Add or IP address Deletion parameters was not understood, IP address Add or IP address Deletion parameters was not
the endpoint MUST consider the operation failed and MUST NOT attempt understood, the endpoint MUST consider the operation failed and
to send any subsequent Add or Delete requests to the peer. MUST NOT attempt to send any subsequent Add or Delete requests to
the peer.
D3b) If an endpoint receives an Error Cause TLV indicating that the D3b) If an endpoint receives an Error Cause TLV indicating that the
IP address Set Primary IP Address parameter was not understood, IP address Set Primary IP Address parameter was not understood,
the endpoint MUST consider the operation failed and MUST NOT attempt the endpoint MUST consider the operation failed and MUST NOT
to send any subsequent Set Primary IP Address requests to the peer. attempt to send any subsequent Set Primary IP Address requests to
the peer.
D4) When deleting an IP address from an association, the IP address D4) When deleting an IP address from an association, the IP address
MUST be considered a valid destination address for the reception of MUST be considered a valid destination address for the reception
SCTP packets until the ASCONF-ACK arrives and MUST NOT be used as a of SCTP packets until the ASCONF-ACK arrives and MUST NOT be used
source address for any subsequent packets. This means that any as a source address for any subsequent packets. This means that
datagrams that arrive before the ASCONF-ACK destined to the IP address any datagrams that arrive before the ASCONF-ACK destined to the IP
being deleted MUST be considered part of the current address being deleted MUST be considered part of the current
association. One special consideration is that ABORT chunks arriving association. One special consideration is that ABORT chunks
destined to the IP address being deleted MUST be ignored (see arriving destined to the IP address being deleted MUST be ignored
Section 4.3.1 for further details). (see Section 4.3.1 for further details).
D5) An endpoint MUST NOT delete its last remaining IP address from an D5) An endpoint MUST NOT delete its last remaining IP address from an
association. In other words if an endpoint is NOT multi-homed it association. In other words if an endpoint is NOT multi-homed it
MUST NOT use the delete IP address without an add IP address preceding MUST NOT use the delete IP address without an add IP address
the delete parameter in the ASCONF chunk. Or if an endpoint sends preceding the delete parameter in the ASCONF chunk. Or if an
multiple requests to delete IP addresses it MUST NOT delete all endpoint sends multiple requests to delete IP addresses it MUST
of the IP addresses that the peer has listed for the requester. NOT delete all of the IP addresses that the peer has listed for
the requester.
D6) An endpoint MUST NOT set an IP header source address for an SCTP D6) An endpoint MUST NOT set an IP header source address for an SCTP
packet holding the ASCONF Chunk to be the same as an address being packet holding the ASCONF Chunk to be the same as an address being
deleted by the ASCONF Chunk. deleted by the ASCONF Chunk.
D7) If a request is received to delete the last remaining IP address D7) If a request is received to delete the last remaining IP address
of a peer endpoint, the receiver MUST send an Error Cause TLV with of a peer endpoint, the receiver MUST send an Error Cause TLV with
the error cause set to the new error code 'Request to Delete Last the error cause set to the new error code 'Request to Delete Last
Remaining IP Address'. The requested delete MUST NOT be performed or Remaining IP Address'. The requested delete MUST NOT be performed
acted upon, other than to send the ASCONF-ACK. or acted upon, other than to send the ASCONF-ACK.
D8) If a request is received to delete an IP address which is also D8) If a request is received to delete an IP address which is also
the source address of the IP packet which contained the ASCONF the source address of the IP packet which contained the ASCONF
chunk, the receiver MUST reject this request. To reject the request chunk, the receiver MUST reject this request. To reject the
the receiver MUST send an Error Cause TLV set to the new error code request the receiver MUST send an Error Cause TLV set to the new
'Request to Delete Source IP Address' (unless Rule D5 has also been error code 'Request to Delete Source IP Address' (unless Rule D5
violated, in which case the error code 'Request to Delete Last has also been violated, in which case the error code 'Request to
Remaining IP Address' is sent). Delete Last Remaining IP Address' is sent).
D9) If an endpoint receives an ADD IP address request and does not D9) If an endpoint receives an ADD IP address request and does not
have the local resources to add this new address to the association, have the local resources to add this new address to the
it MUST return an Error Cause TLV set to the new error code association, it MUST return an Error Cause TLV set to the new
'Operation Refused Due to Resource Shortage'. error code 'Operation Refused Due to Resource Shortage'.
D10) If an endpoint receives an 'Out of Resource' error in response D10) If an endpoint receives an 'Out of Resource' error in response
to its request to ADD an IP address to an association, it must to its request to ADD an IP address to an association, it must
either ABORT the association or not consider the address part of the either ABORT the association or not consider the address part of
association. In other words if the endpoint does not ABORT the the association. In other words if the endpoint does not ABORT
association, it must consider the add attempt failed and NOT use the association, it must consider the add attempt failed and NOT
this address since its peer will treat SCTP packets destined to use this address since its peer will treat SCTP packets destined
the address as Out Of The Blue packets. to the address as Out Of The Blue packets.
D11) When an endpoint receiving an ASCONF to add an IP address sends D11) When an endpoint receiving an ASCONF to add an IP address sends
an 'Out of Resource' in its response, it MUST also fail any an 'Out of Resource' in its response, it MUST also fail any
subsequent add or delete requests bundled in the ASCONF. The subsequent add or delete requests bundled in the ASCONF. The
receiver MUST NOT reject an ADD and then accept a subsequent DELETE receiver MUST NOT reject an ADD and then accept a subsequent
of an IP address in the same ASCONF Chunk. In other words, once a DELETE of an IP address in the same ASCONF Chunk. In other words,
receiver begins failing any ADD or DELETE request, it must fail all once a receiver begins failing any ADD or DELETE request, it must
subsequent ADD or DELETE requests contained in that single ASCONF. fail all subsequent ADD or DELETE requests contained in that
single ASCONF.
D12) When an endpoint receives a request to delete an IP address D12) When an endpoint receives a request to delete an IP address that
that is the current primary address, it is an implementation is the current primary address, it is an implementation decision
decision as to how that endpoint chooses the new primary address. as to how that endpoint chooses the new primary address.
D13) When an endpoint receives a valid request to DELETE an IP D13) When an endpoint receives a valid request to DELETE an IP
address the endpoint MUST consider the address no longer as part of address the endpoint MUST consider the address no longer as part
the association. It MUST NOT send SCTP packets for the association of the association. It MUST NOT send SCTP packets for the
to that address and it MUST treat subsequent packets received from association to that address and it MUST treat subsequent packets
that address as Out Of The Blue. received from that address as Out Of The Blue.
During the time interval between sending out the ASCONF and During the time interval between sending out the ASCONF and
receiving the ASCONF-ACK it MAY be possible to receive DATA chunks receiving the ASCONF-ACK it MAY be possible to receive DATA chunks
out of order. The following examples illustrate these problems: out of order. The following examples illustrate these problems:
Endpoint-A Endpoint-Z Endpoint-A Endpoint-Z
---------- ---------- ---------- ----------
ASCONF[Add-IP:X]------------------------------> ASCONF[Add-IP:X]------------------------------>
/--ASCONF-ACK /--ASCONF-ACK
/ /
/--------/---New DATA: /--------/---New DATA:
/ / Destination / / Destination
<-------------------/ / IP:X <-------------------/ / IP:X
/ /
<--------------------------/ <--------------------------/
In the above example we see a new IP address (X) being added to In the above example we see a new IP address (X) being added to the
the Endpoint-A. However due to packet re-ordering in the network Endpoint-A. However due to packet re-ordering in the network a new
a new DATA chunk is sent and arrives at Endpoint-A before DATA chunk is sent and arrives at Endpoint-A before the ASCONF-ACK
the ASCONF-ACK confirming the add of the address to the association. confirming the add of the address to the association.
A similar problem exists with the deletion of an IP address as A similar problem exists with the deletion of an IP address as
follows: follows:
Endpoint-A Endpoint-Z Endpoint-A Endpoint-Z
---------- ---------- ---------- ----------
/------------New DATA: /------------New DATA:
/ Destination / Destination
/ IP:X / IP:X
ASCONF [DEL-IP:X]---------/----------------> ASCONF [DEL-IP:X]---------/---------------->
<-----------------/------------------ASCONF-ACK <-----------------/------------------ASCONF-ACK
/ /
/ /
<-------------/ <-------------/
In this example we see a DATA chunk destined to the IP:X (which is In this example we see a DATA chunk destined to the IP:X (which is
about to be deleted) arriving after the deletion is complete. about to be deleted) arriving after the deletion is complete. For
For the ADD case an endpoint SHOULD consider the newly adding IP the ADD case an endpoint SHOULD consider the newly adding IP address
address valid for the association to receive data from during the valid for the association to receive data from during the interval
interval when awaiting the ASCONF-ACK. The endpoint MUST NOT source when awaiting the ASCONF-ACK. The endpoint MUST NOT source data from
data from this new address until the ASCONF-ACK arrives but it may this new address until the ASCONF-ACK arrives but it may receive out
receive out of order data as illustrated and MUST NOT treat this of order data as illustrated and MUST NOT treat this data as an OOTB
data as an OOTB datagram (please see [RFC2960] section 8.4). It MAY datagram (please see RFC2960 [5] section 8.4). It MAY drop the data
drop the data silently or it MAY consider it part of the association silently or it MAY consider it part of the association but it MUST
but it MUST NOT respond with an ABORT. NOT respond with an ABORT.
For the DELETE case, an endpoint MAY respond to the late arriving DATA For the DELETE case, an endpoint MAY respond to the late arriving
packet as an OOTB datagram or it MAY hold the deleting IP address for a DATA packet as an OOTB datagram or it MAY hold the deleting IP
small period of time as still valid. If it treats the DATA packet as address for a small period of time as still valid. If it treats the
an OOTB the peer will silently discard the ABORT (since by the time DATA packet as an OOTB the peer will silently discard the ABORT
the ABORT is sent the peer will have removed the IP address from this (since by the time the ABORT is sent the peer will have removed the
association). If the endpoint elects to hold the IP address valid for IP address from this association). If the endpoint elects to hold
a period of time, it MUST NOT hold it valid longer than 2 RTO the IP address valid for a period of time, it MUST NOT hold it valid
intervals for the destination being removed. longer than 2 RTO intervals for the destination being removed.
4.3.1 A special case for OOTB ABORT chunks 4.3.1 A special case for OOTB ABORT chunks
Another case worth mentioning is illustrated below: Another case worth mentioning is illustrated below:
Endpoint-A Endpoint-Z Endpoint-A Endpoint-Z
---------- ---------- ---------- ----------
New DATA:------------\ New DATA:------------\
Source IP:X \ Source IP:X \
\ \
ASCONF-REQ[DEL-IP:X]----\------------------> ASCONF-REQ[DEL-IP:X]----\------------------>
\ /---------ASCONF-ACK \ /---------ASCONF-ACK
\ / \ /
\----/-----------> OOTB \----/-----------> OOTB
(Ignored <---------------------/-------------ABORT (Ignored <---------------------/-------------ABORT
by rule D4) / by rule D4) /
<---------------------/ <---------------------/
For this case, during the deletion of an IP address, an For this case, during the deletion of an IP address, an Abort MUST be
Abort MUST be ignored if the destination address of the ignored if the destination address of the Abort message is that of a
Abort message is that of a destination being deleted. destination being deleted.
4.3.2 A special case for changing an address. 4.3.2 A special case for changing an address.
In some instances the sender may only have one IP address in an In some instances the sender may only have one IP address in an
association that is being renumbered. When this occurs, the sender association that is being renumbered. When this occurs, the sender
may not be able to send to the peer the appropriate ADD/DELETE pair may not be able to send to the peer the appropriate ADD/DELETE pair
and use the old address as a source in the IP header. For this and use the old address as a source in the IP header. For this
reason the sender MUST fill in the Address Bytes field with an reason the sender MUST fill in the Address Parameter field with an
address that is part of the association (in this case the one being address that is part of the association (in this case the one being
deleted). This will allow the receiver to locate the association deleted). This will allow the receiver to locate the association
without using the source address found in the IP header. without using the source address found in the IP header.
The receiver of such a chunk MUST always first use the source address The receiver of such a chunk MUST always first use the source address
found in the IP header in looking up the association. The found in the IP header in looking up the association. The receiver
receiver should attempt to use the address found in the Address should attempt to use the address found in the Address Bytes field
Bytes field only if the lookup fails using the source address from only if the lookup fails using the source address from the IP header.
the IP header. The receiver MUST reply to the source address The receiver MUST reply to the source address of the packet in this
of the packet in this case which is the new address that case which is the new address that was added by the ASCONF (since the
was added by the ASCONF (since the old address is no longer a part old address is no longer a part of the association after processing).
of the association after processing).
4.4 Setting of the primary address 4.4 Setting of the primary address
A sender of this option may elect to send this combined with A sender of this option may elect to send this combined with a
a deletion or addition of an address. A sender SHOULD only send deletion or addition of an address. A sender SHOULD only send a set
a set primary request to an address that is already considered primary request to an address that is already considered part of the
part of the association. In other words if a sender combines association. In other words if a sender combines a set primary with
a set primary with an add of a new IP address the set primary an add of a new IP address the set primary will be discarded unless
will be discarded unless the add request is to be processed the add request is to be processed BEFORE the set primary (i.e. it
BEFORE the set primary (i.e. it precedes the set primary). precedes the set primary).
A request to set primary MAY also appear in an INIT or INIT-ACK A request to set primary MAY also appear in an INIT or INIT-ACK
chunk. This can give advice to the peer endpoint as to which chunk. This can give advice to the peer endpoint as to which of its
of its addresses the sender of the INIT or INIT-ACK would prefer addresses the sender of the INIT or INIT-ACK would prefer to be used
to be used as the primary address. as the primary address.
The request to set an address as the primary path is an option the The request to set an address as the primary path is an option the
receiver SHOULD perform. It is considered advice to the receiver of receiver SHOULD perform. It is considered advice to the receiver of
the best destination address to use in sending SCTP packets (in the the best destination address to use in sending SCTP packets (in the
requesters view). If a request arrives that asks the receiver to requesters view). If a request arrives that asks the receiver to set
set an address as primary that does not exist, the receiver should an address as primary that does not exist, the receiver should NOT
NOT honor the request, leaving its existing primary address honor the request, leaving its existing primary address unchanged.
unchanged.
5. Abstract description of SCTP addressing 5. Security Considerations
The following text provides a working definitions to discuss The ADD/DELETE of an IP address to an existing association does
addIP. We need to distinguish a list of IP addresses and a wildcard provide an additional mechanism by which existing associations can be
address. This corresponds to binding a set of addresses or binding hijacked. Where the attacker is able to intercept and or alter the
the wildcard INADDR_ANY in a sockets API. Using this notation we can packets sent and received in an association, the use of this feature
thus state the rules for using add-ip. MAY increase the ease with which an association may be overtaken.
This threat SHOULD be considered when deploying a version of SCTP
that makes use of this feature. The IP Authentication Header RFC2402
[3] SHOULD be used when the threat environment requires stronger
integrity protections, but does not require confidentiality. It
should be noted that in the base SCTP specification RFC2960 [5], if
an attacker is able to intercept and or alter packets, even without
this feature it is possible to hijack an existing association; please
refer to Section 11 of RFC2960 [5].
A host is a set of IP addresses H={IP1, ..., IPN} 6. IANA considerations
An sock-endpoint at a host H is a pair of a set of IP addresses and This document defines the following new SCTP parameters, chunks and
a port number: errors:
sE = ({IP1, ..., IPn}, Port) where either {IP1, ..., IPn} is a o Two new chunk types,
subset of H or n=1 and IP1 = Wildcard (we abbreviate wildcard as
'*').
Note: do not confuse sock-endpoint with RFC2960 endpoint definition. o Six parameter types, and
They are logically different. In order to make them equivalent
no wildcards must be used and the subset selected must always
be the whole set i.e.:
If sE = ({IP1, ..., IPn}, Port} is a sock-endpoint and A is an o Three new SCTP error causes.
association for which sE is an sock-endpoint, then
Addr(sE, A) = {IP1, ..., IPn}.
In this special case a sock-endpoint is an endpoint in the sense This document also defines a Adaption code point. The adaption code
of RFC2960. point is a 32 bit interger that is assigned by IANA through an IETF
Consensus action as defined in RFC2434 [4].
The set of IP addresses of an sock-endpoint is defined as Addr(sE) = 7. Acknowledgments
{IP1, ..., IPn}.
The port number of sE is defined as Port(sE) = Port. The authors wish to thank Jon Berger, Peter Lei, John Loughney, Ivan
Arias Rodriguez, Renee Revis, Marshall Rose, and Chip Sharp for their
invaluable comments.
Sock-Endpoint(H,Port) denotes the set of all sock-endpoints with References
port 'Port'.
For two different sock-endpoints sE' and sE'' at the same host with [1] Bradner, S., "The Internet Standards Process -- Revision 3", BCP
the same port number Addr(sE') <> {Wildcard} <> Addr(sE'') holds and 9, RFC 2026, October 1996.
Addr(sE') and Addr(sE'') are disjoint.
This means that exactly one of the following is true: [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Sock-Endpoint(H,Port) is Levels", BCP 14, RFC 2119, March 1997.
- empty [3] Kent, S. and R. Atkinson, "IP Authentication Header", RFC 2402,
- contains one Element sE with Addr(sE)={Wildcard} November 1998.
- contains more than one Element where Addr(sE) <> {Wildcard} and [4] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA
all Addr(sE) are disjoin Considerations Section in RFCs", BCP 26, RFC 2434, October 1998.
While establishing an association A between endpoints sE' and sE'' [5] Stewart, R., Xie, Q., Morneault, K., Sharp, C., Schwarzbauer,
at host H' and H'' two subsets are defined: Addr(sE',A) and H., Taylor, T., Rytina, I., Kalla, M., Zhang, L. and V. Paxson,
Addr(sE'',A). "Stream Control Transmission Protocol", RFC 2960, October 2000.
Addr(sE',A) is defined: Authors' Addresses
If Addr(sE') is the {Wildcard} then Randall R. Stewart
Addr(sE',A) is a subset of H' Cisco Systems, Inc.
else 8725 West Higgins Road
Addr(sE',A) is subset of Addr(sE') Suite 300
Chicago, IL 60631
USA
The subset may be defined by scoping of the addresses set for Phone: +1-815-477-2127
routeablility. EMail: rrs@cisco.com
Addr(sE,A) thus describes the set of IP addresses of E used for A Michael A. Ramalho
(Note this definition is the canonical endpoint represented in Cisco Systems, Inc.
[RFC2960]). 1802 Rue de la Porte
Wall Township, NJ 07719-3784
USA
This is because Addr(sE',A) is what sE' sends in its INIT/INIT-ACK Phone: +1.732.449.5762
to sE'' and Addr(sE'',A) is what sE'' sends in its INIT/INIT-ACK to EMail: mramalho@cisco.com
sE'. This is consistent with RFC2960. When you perform either add-ip Qiaobing Xie
or delete-ip later on in the life of the association, you are simply Motorola, Inc.
modifying Addr(sE',A) and Addr(sE'',A). 1501 W. Shure Drive, #2309
Arlington Heights, IL 60004
USA
Association establishment between sE' and sE'' can be seen as: Phone: +1-847-632-3028
EMail: qxie1@email.mot.com
1. sE' and sE'' do exist before the association. The same is thus Michael Tuexen
true for H' and H''. Therefore Addr(sE') and Addr(sE'') are known. Siemens AG
This corresponds to sockets bound to some addresses or INADDR_ANY. ICN WN CS SE 5
D-81359 Munich
Germany
Note: the binding function can be either specific or wildcarded. Phone: +49 89 722 47210
When it is specific we have, Addr(sE') <= H'; where "=" happens when EMail: Michael.Tuexen@icn.siemens.de
we specifically bind every addresses of H' to sE'. When it is
wildcarded we have, Addr(sE') == H'; A wildcard is resolved at the
point of time when an association is established.
2. When an association is setup between a pair of endpoints the Ian Rytina
following is performed: Ericsson
37/360 Elizabeth Street
Melbourne Victoria
Australia
A. Introduce a temporary Set S' and S'' where: Phone: +61-3-9301-6164
If Addr(sE') is the wildcard EMail: ian.rytina@ericsson.com
S' = H'
else
S' = Addr(sE')
B. Replace S' by a subset of S' by some limitation (address Maria-Carmen Belinchon
scoping for example). So S' <= Addr(sE'); In some cases Ericsson
this may not reduce the set of addresses.
In other words S' is a subset (or full-set) of Addr(sE'), Spain
determined by applying some specific limitation/scoping rules
to Addr(sE') at a specific point in time.
The same is true for S''. Phone:
EMail: emecbv@madrid.es.eu.ericsson.se
Phillip T. Conrad
Temple University
CIS Department
Room 303, Computer Building (038-24)
1805 N. Broad St.
Philadelphia, PA 19122
US
C. S' and S'' are the addresses used by the association. So if sE' is Phone: +1 215 204 7910
the client (the one sending the INIT), you generate S' first and EMail: conrad@acm.org
then, send the INIT using the generated address set S'. URI: http://www.cis.temple.edu/~conrad
3. After the association has been established Addr(sE', A) = S' and Appendix A. Abstract Address Handling
Addr(sE'',A) = S'' for this association.
Thus the correct definition is the following: A.1 General remarks
An association is a pair of pairs A=((sE', S'), (sE'',S'')). We The following text provides a working definition of the endpoint
define Addr(sE',A)=S' with the restriction that Addr(sE',A) is a notion to discuss address reconfiguration. It is not intended to
subset of Addr(sE') if Addr(sE') is not the wildcard. If Addr(sE') restrict implementations in any way, its goal is to provide as set of
is the wildcard then Addr(sE',A) is a subset of H'. definitions only. Using these definitions should make a discussion
about address issues easier.
The following are the rules that can then be applied when using A.2 Generalized endpoints
add-ip with these definition:
R1) If Addr(sE) = {Wildcard} then when H gets a new element, it is A generalized endpoint is a pair of a set of IP addresses and a port
automatically added to sE. number at any given point of time. The precise definition is as
follows:
R1.1) You MAY add that address to Addr(sE, A) for all associations A generalized endpoint gE at time t is given by
where sE belongs to A using an ASCONF.
R2) If Addr(sE) <> {Wildcard} you can explicitly add an Address of H gE(t) = ({IP1, ..., IPn}, Port)
(possibly a new one) to Addr(sE) if this address is not an Element
of Addr(sE') for all sE <> sE' in Endpoint(H, Port(E)).
R2.1) You MAY add that address to Addr(sE, A) for all associations where {IP1, ..., IPn} is a non empty set of IP addresses.
where sE belongs to A using an ASCONF.
R3) An address may be deleted from Addr(sE,A) reducing S' to a Please note that the dynamic addition and deletion of IP-addresses
smaller sub-set. described in this document allows the set of IP-addresses of a
generalized endpoint to be changed at some point of time. The port
number can never be changed.
R4) An address may be deleted from endpoint E with the following The set of IP addresses of a generalized endpoint gE at a time t is
considerations: defined as
If Addr(sE) = {*} then Addr(gE)(t) = {IP1, ..., IPn}
any address of Addr(sE,A) can be removed anytime.
else
An address can be removed from sE only after it has
been removed form all associations sE belongs to.
Note that during the removal of an address (before all if gE(t) = ({IP1, ..., IPn}, Port) holds at time t.
associations have removed the address for Addr(sE,A)) an
endpoint sE SHOULD NOT put the address being deleted in
any new S' chosen for new associations.
R5) You can delete an address from H only after it has been removed The port number of a generalized endpoint gE is defined as
from all socket-endpoints at host H.
Note that R5) applies to the logical removal of the address Port(gE) = Port
from a host NOT the physical removal. When an address is
physically removed, it stays logically a part of the host
until it is removed from all socket-endpoints and associations.
During this period the selection for S' MUST be modified NOT
to include the address being removed.
6. Security Considerations if gE(t) = ({IP1, ..., IPn}, Port) holds at time t.
The ADD/DELETE of an IP address to an existing association does There is one fundamental rule which restricts all generalized
provide an additional mechanism by which existing associations can endpoints:
be hijacked. Where the attacker is able to intercept and or alter
the packets sent and received in an association, the use of this
feature MAY increase the ease with which an association may be
overtaken. This threat SHOULD be considered when deploying a version
of SCTP that makes use of this feature. The IP Authentication Header
[RFC2402] SHOULD be used when the threat environment requires
stronger integrity protections, but does not require
confidentiality. It should be noted that in the base SCTP
specification [RFC2960], if an attacker is able to intercept and or
alter packets, even without this feature it is possible to hijack an
existing association; please refer to Section 11 of RFC2960.
7. IANA considerations For two different generalized endpoints gE' and gE'' with the same
port number Port(gE') = Port(gE'') the address sets Addr(gE')(t) and
Addr(gE'')(t) must be disjoint at every point of time.
This document defines the following new SCTP parameters, chunks A.3 Associations
and errors:
- Two new chunk types, Associations consists of two generalized endpoints and the two
- Six parameter types, and address sets known by the peer at any time. The precise definition
- Three new SCTP error causes. is as follows:
8. Acknowledgments An association A between to different generalized endpoints gE' and
gE'' is given by
The authors wish to thank Jon Berger, Peter Lei, John Loughney, Ivan A = (gE', S', gE'', S'')
Arias Rodriguez, Renee Revis, Marshall Rose, and Chip Sharp for
their invaluable comments.
9. Authors' Addresses where S'(t) and S''(t) are set of addresses at any time t such that
S'(t) is a non-empty subset of Addr(gE')(t) and S''(t) is a non-empty
subset of Addr(gE'')(t).
Randall R. Stewart Tel: +1-815-477-2127 If A = (gE', S', gE'', S'') is an association between the generalized
Cisco Systems, Inc. EMail: rrs@cisco.com endpoints gE' and gE'' the following notion is used:
8745 W. Higgins Road, Suite 200
Chicago, Ill 60631
USA
Micheal A. Ramalho Tel: +1-732-809-0188 Addr(A, gE') = S' and Addr(A, gE'') = S''.
Cisco Systems, Inc. EMail: mramalho@cisco.com
1802 Rue de la Porte
Wall Township, NJ 0719-3784
Qiaobing Xie Tel: +1-847-632-3028
Motorola, Inc. EMail: qxie1@email.mot.com
1501 W. Shure Drive, #2309
Arlington Heights, IL 60004
USA
Michael Tuexen Tel: +49-89-722-47210 If the dependency on time is important the notion Addr(A, gE')(t) =
SIEMENS AG EMail: Michael.Tuexen@icn.siemens.de S'(t) will be used.
Hofmannstr. 51
81359 Munich
Germany
Ian Rytina Tel: +61-3-9301-6164 If A is an association between gE' and gE'' then Addr(A, gE') is the
Ericsson Australia EMail:ian.rytina@ericsson.com subset of IP addresses of gE' which is known by gE'' and used by gE'.
37/360 Elizabeth Street
Melbourne, Victoria 3000
Australia
Maria-Carmen Belinchon Association establishment between gE' and gE'' can be seen as:
EMail:emecbv@madrid.es.eu.ericsson.se
Phil Conrad Tel: +1-215-204-7910 1. gE' and gE'' do exist before the association.
Netlab Research Group Email conrad@acm.org
Dept. Of Computer &
Information Sciences
Temple University
1805 N Broad St.
Philadelphia, PA 19122
USA
10. Normative References 2. If an INIT has to be send from gE' to gE'' address scoping rules
and other limitations are applied to calculate the subset S' from
Addr(gE'). The addresses of S' are included in the INIT chunk.
[RFC2960] R. R. Stewart, Q. Xie, K. Morneault, C. Sharp, 3. If an INIT-ACK has to be send from gE'' to gE' address scoping
H. J. Schwarzbauer, T. Taylor, I. Rytina, M. Kalla, L. Zhang, rules and other limitations are applied to calculate the subset
and, V. Paxson, "Stream Control Transmission Protocol," RFC S'' from Addr(gE''). The addresses of S'' are included in the
2960, October 2000. INIT-ACK chunk.
[RFC2026] Bradner, S., "The Internet Standards Process -- Revision 4. After the handshake the association A = (gE', S', gE'', S'') has
3", RFC 2026, October 1996. been established.
[RFC2119] Bradner, S. "Key words for use in RFCs to Indicate 5. Right after the association establishment Addr(A, gE') and
Requirement Levels", BCP 14, RFC 2119, March 1997. Addr(A, gE'') are the addresses which have been seen on the wire
during the handshake.
[RFC2402] S. Kent, R. Atkinson., "IP Authentication Header.", RFC A.4 Relationship with RFC 2960
2402, November 1998.
This Internet Draft expires in 6 months from May, 2001 RFC2960 [5] defines the notion of an endpoint. This subsection will
show that these endpoints are also (special) generalized endpoints.
RFC2960 [5] has no notion of address scoping or other address
handling limitations and provides no mechanism to change the
addresses of an endpoint.
This means that an endpoint is simply a generalized endpoint which
does not depend on the time. Neither the Port nor the address list
changes.
During association setup no address scoping rules or other
limitations will be applied. This means that for an association A
between two endpoints gE' and gE'' the following is true:
Addr(A, gE') = Addr(gE') and Addr(A, gE'') = Addr(gE'').
A.5 Rules for address manipulation
The rules for address manipulation can now be stated in a simple way:
1. An address can be added to a generalized endpoint gE only if this
address is not an address of a different generalized endpoint
with the same port number.
2. An address can be added to an association A with generalized
endpoint gE if it has been added to the generalized endpoint gE
first. This means that the address must be an element of
Addr(gE) first and then it can become an element of Addr(A, gE).
But this is not necessary. If the association does not allow the
reconfiguration of the addresses only Addr(gE) can be modified.
3. An address can be deleted from an association A with generalized
endpoint gE as long as Addr(A, gE) stays non-empty.
4. An address can be deleted from an generalized endpoint gE only if
it has been removed from all associations having gE as a
generalized endpoint.
These rules simply make sure that the rules for the endpoints and
associations given above are always fulfilled.
Full Copyright Statement
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