draft-ietf-tsvwg-sctp-strrst-09.txt   draft-ietf-tsvwg-sctp-strrst-10.txt 
Network Working Group R. Stewart Network Working Group R. Stewart
Internet-Draft Huawei Internet-Draft Adara Networks
Intended status: Standards Track P. Lei Intended status: Standards Track P. Lei
Expires: July 8, 2011 Cisco Systems, Inc. Expires: December 28, 2011 Cisco Systems, Inc.
M. Tuexen M. Tuexen
Muenster Univ. of Applied Sciences Muenster Univ. of Appl. Sciences
January 4, 2011 June 26, 2011
Stream Control Transmission Protocol (SCTP) Stream Reconfiguration Stream Control Transmission Protocol (SCTP) Stream Reconfiguration
draft-ietf-tsvwg-sctp-strrst-09.txt draft-ietf-tsvwg-sctp-strrst-10.txt
Abstract Abstract
Many applications that use SCTP want the ability to "reset" a stream. Many applications that use SCTP want the ability to "reset" a stream.
The intention of resetting a stream is to set the numbering sequence The intention of resetting a stream is to set the numbering sequence
of the stream back to 'zero' with a corresponding notification to the of the stream back to 'zero' with a corresponding notification to the
upper layer that this has been performed. The applications that want upper layer that this has been performed. The applications that want
this feature want it so that they can "re-use" streams for different this feature want it so that they can "re-use" streams for different
purposes but still utilize the stream sequence number so that the purposes but still utilize the stream sequence number so that the
application can track the message flows. Thus, without this feature, application can track the message flows. Thus, without this feature,
skipping to change at page 1, line 44 skipping to change at page 1, line 44
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on July 8, 2011. This Internet-Draft will expire on December 28, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. New Chunk Type . . . . . . . . . . . . . . . . . . . . . . . . 4 3. New Chunk Type . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. STREAM RESET Chunk . . . . . . . . . . . . . . . . . . . . 5 3.1. RE-CONFIG Chunk . . . . . . . . . . . . . . . . . . . . . 5
4. New Parameter Types . . . . . . . . . . . . . . . . . . . . . 6 4. New Parameter Types . . . . . . . . . . . . . . . . . . . . . 6
4.1. Outgoing SSN Reset Request Parameter . . . . . . . . . . . 6 4.1. Outgoing SSN Reset Request Parameter . . . . . . . . . . . 6
4.2. Incoming SSN Reset Request Parameter . . . . . . . . . . . 8 4.2. Incoming SSN Reset Request Parameter . . . . . . . . . . . 8
4.3. SSN/TSN Reset Request Parameter . . . . . . . . . . . . . 9 4.3. SSN/TSN Reset Request Parameter . . . . . . . . . . . . . 9
4.4. Stream Reset Response Parameter . . . . . . . . . . . . . 9 4.4. Re-configuration Response Parameter . . . . . . . . . . . 9
4.5. Add Outgoing Streams Request Parameter . . . . . . . . . . 11 4.5. Add Outgoing Streams Request Parameter . . . . . . . . . . 11
5. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 12 5. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.1. Sender Side Procedures . . . . . . . . . . . . . . . . . . 12 5.1. Sender Side Procedures . . . . . . . . . . . . . . . . . . 12
5.1.1. Sender Side Procedures for the Stream Reset Chunk . . 12 5.1.1. Sender Side Procedures for the RE-CONFIG Chunk . . . . 12
5.1.2. Sender Side Procedures for the Outgoing SSN Reset 5.1.2. Sender Side Procedures for the Outgoing SSN Reset
Request Parameter . . . . . . . . . . . . . . . . . . 13 Request Parameter . . . . . . . . . . . . . . . . . . 13
5.1.3. Sender Side Procedures for the Incoming SSN Reset 5.1.3. Sender Side Procedures for the Incoming SSN Reset
Request Parameter . . . . . . . . . . . . . . . . . . 14 Request Parameter . . . . . . . . . . . . . . . . . . 14
5.1.4. Sender Side Procedures for the SSN/TSN Reset 5.1.4. Sender Side Procedures for the SSN/TSN Reset
Request Parameter . . . . . . . . . . . . . . . . . . 15 Request Parameter . . . . . . . . . . . . . . . . . . 15
5.1.5. Sender Side Procedures for the Stream Reset 5.1.5. Sender Side Procedures for the Re-configuration
Response Parameter . . . . . . . . . . . . . . . . . . 15 Response Parameter . . . . . . . . . . . . . . . . . . 15
5.1.6. Sender Side Procedures for the Add Outgoing 5.1.6. Sender Side Procedures for the Add Outgoing
Streams Request Parameter . . . . . . . . . . . . . . 16 Streams Request Parameter . . . . . . . . . . . . . . 16
5.2. Receiver Side Procedures . . . . . . . . . . . . . . . . . 16 5.2. Receiver Side Procedures . . . . . . . . . . . . . . . . . 16
5.2.1. Receiver Side Procedures for the Stream Reset Chunk . 16 5.2.1. Receiver Side Procedures for the RE-CONFIG Chunk . . . 16
5.2.2. Receiver Side Procedures for the Outgoing SSN 5.2.2. Receiver Side Procedures for the Outgoing SSN
Reset Request Parameter . . . . . . . . . . . . . . . 17 Reset Request Parameter . . . . . . . . . . . . . . . 17
5.2.3. Receiver Side Procedures for the Incoming SSN 5.2.3. Receiver Side Procedures for the Incoming SSN
Reset Request Parameter . . . . . . . . . . . . . . . 18 Reset Request Parameter . . . . . . . . . . . . . . . 18
5.2.4. Receiver Side Procedures for the SSN/TSN Reset 5.2.4. Receiver Side Procedures for the SSN/TSN Reset
Request Parameter . . . . . . . . . . . . . . . . . . 19 Request Parameter . . . . . . . . . . . . . . . . . . 19
5.2.5. Receiver Side Procedures for the Add Outgoing 5.2.5. Receiver Side Procedures for the Add Outgoing
Streams Request Parameter . . . . . . . . . . . . . . 19 Streams Request Parameter . . . . . . . . . . . . . . 19
5.2.6. Receiver Side Procedures for the Stream Reset 5.2.6. Receiver Side Procedures for the Re-configuration
Response Parameter . . . . . . . . . . . . . . . . . . 19 Response Parameter . . . . . . . . . . . . . . . . . . 19
6. Socket API Considerations . . . . . . . . . . . . . . . . . . 20 6. Socket API Considerations . . . . . . . . . . . . . . . . . . 20
6.1. Events . . . . . . . . . . . . . . . . . . . . . . . . . . 20 6.1. Events . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.1.1. Stream Reset Event . . . . . . . . . . . . . . . . . . 21 6.1.1. Stream Reset Event . . . . . . . . . . . . . . . . . . 21
6.1.2. Association Reset Event . . . . . . . . . . . . . . . 22 6.1.2. Association Reset Event . . . . . . . . . . . . . . . 22
6.1.3. Stream Change Event . . . . . . . . . . . . . . . . . 23 6.1.3. Stream Change Event . . . . . . . . . . . . . . . . . 23
6.2. Event Subscription . . . . . . . . . . . . . . . . . . . . 24 6.2. Event Subscription . . . . . . . . . . . . . . . . . . . . 24
6.3. Socket Options . . . . . . . . . . . . . . . . . . . . . . 25 6.3. Socket Options . . . . . . . . . . . . . . . . . . . . . . 24
6.3.1. Enable/Disable Stream Reset 6.3.1. Enable/Disable Stream Reset
(SCTP_ENABLE_STREAM_RESET) . . . . . . . . . . . . . . 25 (SCTP_ENABLE_STREAM_RESET) . . . . . . . . . . . . . . 25
6.3.2. Reset Incoming and/or Outgoing Streams 6.3.2. Reset Incoming and/or Outgoing Streams
(SCTP_RESET_STREAMS) . . . . . . . . . . . . . . . . . 26 (SCTP_RESET_STREAMS) . . . . . . . . . . . . . . . . . 26
6.3.3. Reset SSN/TSN (SCTP_RESET_ASSOC) . . . . . . . . . . . 27 6.3.3. Reset SSN/TSN (SCTP_RESET_ASSOC) . . . . . . . . . . . 26
6.3.4. Add Outgoing Streams (SCTP_ADD_OUT_STREAMS) . . . . . 27 6.3.4. Add Outgoing Streams (SCTP_ADD_OUT_STREAMS) . . . . . 27
7. Security Considerations . . . . . . . . . . . . . . . . . . . 28 7. Security Considerations . . . . . . . . . . . . . . . . . . . 27
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28
8.1. A New Chunk Type . . . . . . . . . . . . . . . . . . . . . 29 8.1. A New Chunk Type . . . . . . . . . . . . . . . . . . . . . 28
8.2. Five New Parameter Types . . . . . . . . . . . . . . . . . 29 8.2. Five New Parameter Types . . . . . . . . . . . . . . . . . 28
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 29 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 29
Appendix A. Examples of the Stream Reset procedures . . . . . . . 30 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 29
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 31 10.1. Normative References . . . . . . . . . . . . . . . . . . . 29
10.1. Normative References . . . . . . . . . . . . . . . . . . . 31 10.2. Informative References . . . . . . . . . . . . . . . . . . 29
10.2. Informative References . . . . . . . . . . . . . . . . . . 31 Appendix A. Examples of the Re-configuration procedures . . . . . 30
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 31 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 31
1. Introduction 1. Introduction
Many applications that use SCTP want the ability to "reset" a stream. Many applications that use SCTP want the ability to "reset" a stream.
The intention of resetting a stream is to set the numbering sequence The intention of resetting a stream is to set the numbering sequence
of the stream back to 'zero' with a corresponding notification to the of the stream back to 'zero' with a corresponding notification to the
upper layer that this has been performed. The applications that want upper layer that this has been performed. The applications that want
this feature want to "re-use" streams for different purposes but this feature want to "re-use" streams for different purposes but
still utilize the stream sequence number so that the application can still utilize the stream sequence number so that the application can
skipping to change at page 4, line 34 skipping to change at page 4, line 34
via the socket API for TCP. via the socket API for TCP.
2. Conventions 2. Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
3. New Chunk Type 3. New Chunk Type
This section defines the new chunk type that will be used to reset This section defines the new chunk type that will be used to re-
streams. Table 1 illustrates the new chunk type. configure streams. Table 1 illustrates the new chunk type.
+------------+-----------------------------------+ +------------+------------------------------------+
| Chunk Type | Chunk Name | | Chunk Type | Chunk Name |
+------------+-----------------------------------+ +------------+------------------------------------+
| 0x82 | Stream Reset Chunk (STREAM_RESET) | | 0x82 | Re-configuration Chunk (RE-CONFIG) |
+------------+-----------------------------------+ +------------+------------------------------------+
Table 1 Table 1
It should be noted that the format of the STREAM_RESET chunk requires It should be noted that the format of the RE-CONFIG chunk requires
the receiver to ignore the chunk if it is not understood and continue the receiver to ignore the chunk if it is not understood and continue
processing all chunks that follow. This is accomplished by the use processing all chunks that follow. This is accomplished by the use
of the upper bits of the chunk type as described in section 3.2 of of the upper bits of the chunk type as described in section 3.2 of
[RFC4960]. [RFC4960].
All transported integer numbers are in "network byte order" a.k.a., All transported integer numbers are in "network byte order" a.k.a.,
Big Endian. Big Endian.
3.1. STREAM RESET Chunk 3.1. RE-CONFIG Chunk
This document adds one new chunk type to SCTP. The chunk has the This document adds one new chunk type to SCTP. The chunk has the
following format: following format:
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 = 0x82 | Chunk Flags | Chunk Length | | Type = 0x82 | Chunk Flags | Chunk Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stream Reset Parameter | \ \
/ Re-configuration Parameter /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stream Reset Parameter (optional) | \ \
/ Re-configuration Parameter (optional) /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Chunk Type: 1 byte (unsigned integer) Chunk Type: 1 byte (unsigned integer)
This field holds the IANA defined chunk type for the STREAM RESET This field holds the IANA defined chunk type for the RE-CONFIG
chunk. The suggested value of this field for IANA is 0x82. chunk. The suggested value of this field for IANA is 0x82.
Chunk Flags: 1 byte (unsigned integer) Chunk Flags: 1 byte (unsigned integer)
This field is set to 0 by the sender and ignored by the receiver. This field is set to 0 by the sender and ignored by the receiver.
Chunk Length: 2 bytes (unsigned integer) Chunk Length: 2 bytes (unsigned integer)
This field holds the length of the chunk in bytes, including the This field holds the length of the chunk in bytes, including the
Chunk Type, Chunk Flags and Chunk Length. Chunk Type, Chunk Flags and Chunk Length.
Stream Reset Parameter Re-configuration Parameter
This field holds a Stream Reset Request Parameter or a Stream This field holds a Re-configuration Request Parameter or a Re-
Reset Response Parameter. configuration Response Parameter.
Note that each STREAM RESET chunk holds at least one parameter and at Note that each RE-CONFIG chunk holds at least one parameter and at
most two parameters. Only the following combinations are allowed: most two parameters. Only the following combinations are allowed:
1. Outgoing SSN Reset Request Parameter. 1. Outgoing SSN Reset Request Parameter.
2. Incoming SSN Reset Request Parameter. 2. Incoming SSN Reset Request Parameter.
3. Outgoing SSN Reset Request Parameter, Incoming SSN Reset Request 3. Outgoing SSN Reset Request Parameter, Incoming SSN Reset Request
Parameter. Parameter.
4. SSN/TSN Reset Request Parameter. 4. SSN/TSN Reset Request Parameter.
5. Add Outgoing Streams Request Parameter. 5. Add Outgoing Streams Request Parameter.
6. Stream Reset Response Parameter. 6. Re-configuration Response Parameter.
7. Stream Reset Response Parameter, Outgoing SSN Reset Request 7. Re-configuration Response Parameter, Outgoing SSN Reset Request
Parameter. Parameter.
8. Stream Reset Response Parameter, Stream Reset Response Parameter. 8. Re-configuration Response Parameter, Re-configuration Response
Parameter.
If a sender transmits an unsupported combination, the receiver SHOULD If a sender transmits an unsupported combination, the receiver SHOULD
send an ERROR chunk with a Protocol Violation cause as defined in send an ERROR chunk with a Protocol Violation cause as defined in
section 3.3.10.13 of [RFC4960]). section 3.3.10.13 of [RFC4960]).
4. New Parameter Types 4. New Parameter Types
This section defines the new parameter types that will be used in the This section defines the new parameter types that will be used in the
STREAM_RESET chunk. Table 2 illustrates the new parameter types. RE-CONFIG chunk. Table 2 illustrates the new parameter types.
+----------------+----------------------------------------+ +----------------+----------------------------------------+
| Parameter Type | Parameter Name | | Parameter Type | Parameter Name |
+----------------+----------------------------------------+ +----------------+----------------------------------------+
| 0x000d | Outgoing SSN Reset Request Parameter | | 0x000d | Outgoing SSN Reset Request Parameter |
| 0x000e | Incoming SSN Reset Request Parameter | | 0x000e | Incoming SSN Reset Request Parameter |
| 0x000f | SSN/TSN Reset Request Parameter | | 0x000f | SSN/TSN Reset Request Parameter |
| 0x0010 | Stream Reset Response Parameter | | 0x0010 | Re-configuration Response Parameter |
| 0x0011 | Add Outgoing Streams Request Parameter | | 0x0011 | Add Outgoing Streams Request Parameter |
+----------------+----------------------------------------+ +----------------+----------------------------------------+
Table 2 Table 2
It should be noted that the parameter format requires the receiver to It should be noted that the parameter format requires the receiver to
stop processing the parameter and not to process any further stop processing the parameter and not to process any further
parameters within the chunk if the parameter type is not recognized. parameters within the chunk if the parameter type is not recognized.
This is accomplished by the use of the upper bits of the parameter This is accomplished by the use of the upper bits of the parameter
type as described in section 3.2.1 of [RFC4960]. type as described in section 3.2.1 of [RFC4960].
skipping to change at page 7, line 10 skipping to change at page 7, line 10
4.1. Outgoing SSN Reset Request Parameter 4.1. Outgoing SSN Reset Request Parameter
This parameter is used by the sender to request the reset of some or This parameter is used by the sender to request the reset of some or
all outgoing streams. all outgoing streams.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Parameter Type = 0x000d | Parameter Length = 16 + 2 * N | | Parameter Type = 0x000d | Parameter Length = 16 + 2 * N |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stream Reset Request Sequence Number | | Re-configuration Request Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stream Reset Response Sequence Number | | Re-configuration Response Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender's Last Assigned TSN | | Sender's Last Assigned TSN |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stream Number 1 (optional) | Stream Number 2 (optional) | | Stream Number 1 (optional) | Stream Number 2 (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ ...... / / ...... /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stream Number N-1 (optional) | Stream Number N (optional) | | Stream Number N-1 (optional) | Stream Number N (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameter Type: 2 bytes (unsigned integer) Parameter Type: 2 bytes (unsigned integer)
This field holds the IANA defined parameter type for Stream Reset This field holds the IANA defined parameter type for the Outgoing
Request Parameter. The suggested value of this field for IANA is SSN Reset Request Parameter. The suggested value of this field
0x000d. for IANA is 0x000d.
Parameter Length: 2 bytes (unsigned integer) Parameter Length: 2 bytes (unsigned integer)
This field holds the length in bytes of the parameter; the value This field holds the length in bytes of the parameter; the value
MUST be 16 + 2 * N. MUST be 16 + 2 * N.
Stream Reset Request Sequence Number: 4 bytes (unsigned integer) Re-configuration Request Sequence Number: 4 bytes (unsigned integer)
This field is used to identify the request. It is a monotonically This field is used to identify the request. It is a monotonically
increasing number that is initialized to the same value as the increasing number that is initialized to the same value as the
Initial TSN number. It is increased by 1 whenever sending a new Initial TSN number. It is increased by 1 whenever sending a new
Stream Reset Request parameter. Re-configuration Request parameter.
Stream Reset Response Sequence Number: 4 bytes (unsigned integer) Re-configuration Response Sequence Number: 4 bytes (unsigned
integer)
When this Outgoing SSN Reset Request Parameter is sent in response When this Outgoing SSN Reset Request Parameter is sent in response
to an Incoming SSN Reset Request Parameter this parameter is also to an Incoming SSN Reset Request Parameter this parameter is also
an implicit response to the incoming request. Then this field an implicit response to the incoming request. Then this field
holds the Stream Reset Request Sequence Number of the incoming holds the Re-configuration Request Sequence Number of the incoming
request. In other cases it holds the next expected Stream Reset request. In other cases it holds the next expected Re-
Request Sequence Number minus 1. configuration Request Sequence Number minus 1.
Sender's last assigned TSN: 4 bytes (unsigned integer) Sender's last assigned TSN: 4 bytes (unsigned integer)
This value holds the next TSN minus 1, in other words the last TSN This value holds the next TSN minus 1, in other words the last TSN
that this sender assigned. that this sender assigned.
Stream Number 1..N: 2 bytes (unsigned integer) Stream Number 1..N: 2 bytes (unsigned integer)
This optional field, if included, is used to indicate specific This optional field, if included, is used to indicate specific
streams that are to be reset. If no streams are listed, then all streams that are to be reset. If no streams are listed, then all
streams are to be reset. streams are to be reset.
This parameter can appear in a STREAM RESET chunk. This parameter This parameter can appear in a RE-CONFIG chunk. This parameter MUST
MUST NOT appear in any other chunk type. NOT appear in any other chunk type.
4.2. Incoming SSN Reset Request Parameter 4.2. Incoming SSN Reset Request Parameter
This parameter is used by the sender to request that the peer resets This parameter is used by the sender to request that the peer resets
some or all of its outgoing streams. some or all of its outgoing streams.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Parameter Type = 0x000e | Parameter Length = 8 + 2 * N | | Parameter Type = 0x000e | Parameter Length = 8 + 2 * N |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stream Reset Request Sequence Number | | Re-configuration Request Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stream Number 1 (optional) | Stream Number 2 (optional) | | Stream Number 1 (optional) | Stream Number 2 (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ ...... / / ...... /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stream Number N-1 (optional) | Stream Number N (optional) | | Stream Number N-1 (optional) | Stream Number N (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameter Type: 2 bytes (unsigned integer) Parameter Type: 2 bytes (unsigned integer)
This field holds the IANA defined parameter type for Stream Reset This field holds the IANA defined parameter type for the Incoming
Request Parameter. The suggested value of this field for IANA is SSN Reset Request Parameter. The suggested value of this field
0x000e. for IANA is 0x000e.
Parameter Length: 2 bytes (unsigned integer) Parameter Length: 2 bytes (unsigned integer)
This field holds the length in bytes of the parameter; the value This field holds the length in bytes of the parameter; the value
MUST be 8 + 2 * N. MUST be 8 + 2 * N.
Stream Reset Request Sequence Number: 4 bytes (unsigned integer) Re-configuration Request Sequence Number: 4 bytes (unsigned integer)
This field is used to identify the request. It is a monotonically This field is used to identify the request. It is a monotonically
increasing number that is initialized to the same value as the increasing number that is initialized to the same value as the
Initial TSN number. It is increased by 1 whenever sending a new Initial TSN number. It is increased by 1 whenever sending a new
Stream Reset Request parameter. Re-configuration Request parameter.
Stream Number 1..N: 2 bytes (unsigned integer) Stream Number 1..N: 2 bytes (unsigned integer)
This optional field, if included, is used to indicate specific This optional field, if included, is used to indicate specific
streams that are to be reset. If no streams are listed, then all streams that are to be reset. If no streams are listed, then all
streams are to be reset. streams are to be reset.
This parameter can appear in a STREAM RESET chunk. This parameter This parameter can appear in a RE-CONFIG chunk. This parameter MUST
MUST NOT appear in any other chunk type. NOT appear in any other chunk type.
4.3. SSN/TSN Reset Request Parameter 4.3. SSN/TSN Reset Request Parameter
This parameter is used by the sender to request a reset of the TSN This parameter is used by the sender to request a reset of the TSN
and SSN numbering of all streams. and SSN numbering of all incoming and outgoing streams.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Parameter Type = 0x000f | Parameter Length = 8 | | Parameter Type = 0x000f | Parameter Length = 8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stream Reset Request Sequence Number | | Re-configuration Request Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameter Type: 2 bytes (unsigned integer) Parameter Type: 2 bytes (unsigned integer)
This field holds the IANA defined parameter type for Stream Reset This field holds the IANA defined parameter type for the SSN/TSN
Request Parameter. The suggested value of this field for IANA is Reset Request Parameter. The suggested value of this field for
0x000f. IANA is 0x000f.
Parameter Length: 2 bytes (unsigned integer) Parameter Length: 2 bytes (unsigned integer)
This field holds the length in bytes of the parameter; the value This field holds the length in bytes of the parameter; the value
MUST be 8. MUST be 8.
Stream Reset Request Sequence Number: 4 bytes (unsigned integer) Re-configuration Request Sequence Number: 4 bytes (unsigned integer)
This field is used to identify the request. It is a monotonically This field is used to identify the request. It is a monotonically
increasing number that is initialized to the same value as the increasing number that is initialized to the same value as the
Initial TSN number. It is increased by 1 whenever sending a new Initial TSN number. It is increased by 1 whenever sending a new
Stream Reset Request parameter. Re-configuration Request parameter.
This parameter can appear in a STREAM RESET chunk. This parameter This parameter can appear in a RE-CONFIG chunk. This parameter MUST
MUST NOT appear in any other chunk type. NOT appear in any other chunk type.
4.4. Stream Reset Response Parameter 4.4. Re-configuration Response Parameter
This parameter is used by the receiver of a stream reset request This parameter is used by the receiver of a Re-configuration Request
parameter to respond to the stream reset request. parameter to respond to the request.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Parameter Type = 0x0010 | Parameter Length | | Parameter Type = 0x0010 | Parameter Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stream Reset Response Sequence Number | | Re-configuration Response Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Result | | Result |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender's next TSN (optional) | | Sender's next TSN (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receiver's next TSN (optional) | | Receiver's next TSN (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameter Type: 2 bytes (unsigned integer) Parameter Type: 2 bytes (unsigned integer)
This field holds the IANA defined parameter type for Stream Reset This field holds the IANA defined parameter type for Re-
Response Parameter. The suggested value of this field for IANA is configuration Response Parameter. The suggested value of this
0x0010. field for IANA is 0x0010.
Parameter Type Length: 2 bytes (unsigned integer) Parameter Type Length: 2 bytes (unsigned integer)
This field holds the length in bytes of the parameter; the value This field holds the length in bytes of the parameter; the value
MUST be 12 if the optional fields are not present and 20 MUST be 12 if the optional fields are not present and 20
otherwise. otherwise.
Stream Reset Response Sequence Number: 4 bytes (unsigned integer) Re-configuration Response Sequence Number: 4 bytes (unsigned
integer)
This value is copied from the request parameter and is used by the This value is copied from the request parameter and is used by the
receiver of the Stream Reset Response Parameter to tie the receiver of the Re-configuration Response Parameter to tie the
response to the request. response to the request.
Result: 4 bytes (unsigned integer) Result: 4 bytes (unsigned integer)
This value describes the result of the processing of the request. This value describes the result of the processing of the request.
It is encoded as given by the following table It is encoded as given by the following table
+--------+-------------------------------------+ +--------+-------------------------------------+
| Result | Description | | Result | Description |
+--------+-------------------------------------+ +--------+-------------------------------------+
| 0 | Success - Nothing to do | | 0 | Success - Nothing to do |
skipping to change at page 11, line 18 skipping to change at page 11, line 18
responses to SSN/TSN reset requests. responses to SSN/TSN reset requests.
Receiver's next TSN: 4 bytes (unsigned integer) Receiver's next TSN: 4 bytes (unsigned integer)
This field holds the TSN the receiver of the response must use to This field holds the TSN the receiver of the response must use to
send the next DATA chunk. The field is only applicable in send the next DATA chunk. The field is only applicable in
responses to SSN/TSN reset requests. responses to SSN/TSN reset requests.
Either both optional fields (Sender's next TSN and Receiver's next Either both optional fields (Sender's next TSN and Receiver's next
TSN) MUST be present or none. TSN) MUST be present or none.
This parameter can appear in a STREAM RESET chunk. This parameter This parameter can appear in a RE-CONFIG chunk. This parameter MUST
MUST NOT appear in any other chunk type. NOT appear in any other chunk type.
4.5. Add Outgoing Streams Request Parameter 4.5. Add Outgoing Streams Request Parameter
This parameter is used by the sender to request that an additional This parameter is used by the sender to request that an additional
number of outgoing streams (i.e. the receiver's incoming streams) be number of outgoing streams (i.e. the receiver's incoming streams) be
added to the association. added to the association.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Parameter Type = 0x0011 | Parameter Length = 12 | | Parameter Type = 0x0011 | Parameter Length = 12 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stream Reset Request Sequence Number | | Re-configuration Request Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of new streams | Reserved | | Number of new streams | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameter Type: 2 bytes (unsigned integer) Parameter Type: 2 bytes (unsigned integer)
This field holds the IANA defined parameter type for the Add This field holds the IANA defined parameter type for the the Add
Streams Parameter. The suggested value of this field for IANA is Outgoing Streams Parameter. The suggested value of this field for
0x0011. IANA is 0x0011.
Parameter Length: 2 bytes (unsigned integer) Parameter Length: 2 bytes (unsigned integer)
This field holds the length in bytes of the parameter; the value This field holds the length in bytes of the parameter; the value
MUST be 12. MUST be 12.
Stream Reset Request Sequence Number: 4 bytes (unsigned integer) Re-configuration Request Sequence Number: 4 bytes (unsigned integer)
This field is used to identify the request. It is a monotonically This field is used to identify the request. It is a monotonically
increasing number that is initialized to the same value as the increasing number that is initialized to the same value as the
Initial TSN number. It is increased by 1 whenever sending a new Initial TSN number. It is increased by 1 whenever sending a new
Stream Reset Request parameter. Re-configuration Request parameter.
Number of new streams: 2 bytes (unsigned integer) Number of new streams: 2 bytes (unsigned integer)
This value holds the number of additional outgoing streams the This value holds the number of additional outgoing streams the
sender requests to be added to the association. Streams are added sender requests to be added to the association. Streams are added
in order and are consecutive, e.g. if an association has four in order and are consecutive, e.g. if an association has four
outgoing streams (0-3) and a requested is made to add 3 streams outgoing streams (0-3) and a requested is made to add 3 streams
then the new streams will be 4, 5 and 6. then the new streams will be 4, 5 and 6.
Reserved: 2 bytes (unsigned integer) Reserved: 2 bytes (unsigned integer)
This field is reserved. It SHOULD be set to 0 by the sender and This field is reserved. It SHOULD be set to 0 by the sender and
ignored by the receiver. ignored by the receiver.
This parameter MAY appear in a STREAM RESET chunk. This parameter This parameter MAY appear in a RE-CONFIG chunk. This parameter MUST
MUST NOT appear in any other chunk type. NOT appear in any other chunk type.
5. Procedures 5. Procedures
This section defines the procedures used by both the sender and This section defines the procedures used by both the sender and
receiver of a stream reset. We also give various example stream receiver of a RE-CONFIG chunk. Various examples of re-configuration
reset scenarios. scenarios are given in Appendix A.
One important thing to remember about SCTP streams is that they are One important thing to remember about SCTP streams is that they are
uni-directional and there is no coorespondance between outgoing and uni-directional and there is no coorespondance between outgoing and
incoming streams. The procedures outlined in this section are incoming streams. The procedures outlined in this section are
designed so that the incoming side will always reset their stream designed so that the incoming side will always reset their stream
sequence number first before the outgoing side which means the stream sequence number first before the outgoing side which means the re-
reset request must always originate from the outgoing side. These configuration request must always originate from the outgoing side.
two issues have important ramifications upon how an SCTP endpoint These two issues have important ramifications upon how an SCTP
might request that its incoming streams be reset. In effect it must endpoint might request that its incoming streams be reset. In effect
ask the peer to start an outgoing reset proceedure and once that it must ask the peer to start an outgoing reset proceedure and once
request is acknowledged let the peer actually control the reset that request is acknowledged let the peer actually control the reset
operation. operation.
5.1. Sender Side Procedures 5.1. Sender Side Procedures
This section describes the procedures related to the sending of This section describes the procedures related to the sending of RE-
Stream Reset Chunks. A Stream Reset Chunk is composed of one or two CONFIG chunks. A RE-CONFIG chunk is composed of one or two Type
Type Length Value (TLV) parameters. Length Value (TLV) parameters.
5.1.1. Sender Side Procedures for the Stream Reset Chunk 5.1.1. Sender Side Procedures for the RE-CONFIG Chunk
This SCTP extension uses the Supported Extensions Parameter defined This SCTP extension uses the Supported Extensions Parameter defined
in [RFC5061] for negotiating the support for it. in [RFC5061] for negotiating the support for it.
An SCTP endpoint supporting this extension MUST include the chunk An SCTP endpoint supporting this extension MUST include the chunk
type of the STREAM_RESET chunk in the Supported Extensions Parameter type of the RE-CONFIG chunk in the Supported Extensions Parameter in
in either the INIT or INIT-ACK. Before sending a Stream Reset Chunk either the INIT or INIT-ACK. Before sending a RE-CONFIG chunk the
the sender MUST ensure that the peer advertised support for the sender MUST ensure that the peer advertised support for the re-
stream reset extension. If the chunk type of the STREAM_RESET chunk configuration extension. If the chunk type of the RE-CONFIG chunk
does not appear in the supported extensions list of chunks, then the does not appear in the supported extensions list of chunks, then the
sender MUST NOT send any stream reset request to the peer, and any sender MUST NOT send any re-configuration request to the peer, and
request by the application for such service SHOULD be responded to any request by the application for such service SHOULD be responded
with an appropriate error indicating the peer SCTP stack does not to with an appropriate error indicating the peer SCTP stack does not
support the stream reset extension. support the re-configuration extension.
After packaging the Stream Reset Chunk and sending it to the peer the At any given time there MUST NOT be more than one request be in
sender MUST start a 'Stream Reset Timer' if the STREAM RESET chunk flight. So if the Re-configuration Timer is running and the the RE-
CONFIG chunk contains at least one request parameter the chunk MUST
be buffered.
After packaging the RE-CONFIG chunk and sending it to the peer the
sender MUST start the Re-configuration Timer if the RE-CONFIG chunk
contains at least one request parameter. If it contains no request contains at least one request parameter. If it contains no request
parameter, the Stream Reset Timer MUST NOT be started. This timer parameter, the Re-configuration Timer MUST NOT be started. This
MUST use the same value as SCTP's Data transmission timer (i.e. the timer MUST use the same value as SCTP's Data transmission timer (i.e.
RTO timer) and MUST use exponential backoff doubling the value at the RTO timer) and MUST use exponential backoff doubling the value at
every expiration. If the timer expires, besides doubling the value, every expiration. If the timer expires, besides doubling the value,
the sender MUST retransmit the Stream Reset Chunk, increment the the sender MUST retransmit the RE-CONFIG chunk, increment the
appropriate error counts (both for the association and the appropriate error counts (both for the association and the
destination), and perform threshold management possibly destroying destination), and perform threshold management possibly destroying
the association if SCTP retransmission thresholds are exceeded. the association if SCTP retransmission thresholds are exceeded.
5.1.2. Sender Side Procedures for the Outgoing SSN Reset Request 5.1.2. Sender Side Procedures for the Outgoing SSN Reset Request
Parameter Parameter
When an SCTP sender wants to reset the SSNs of some or all outgoing When an SCTP sender wants to reset the SSNs of some or all outgoing
streams it can send an Outgoing SSN Reset Request Parameter provided streams it can send an Outgoing SSN Reset Request Parameter provided
that the Stream Reset Timer is not running. The following steps must that the Re-configuration Timer is not running. The following steps
be followed: must be followed:
A1: The sender MUST stop assigning new SSNs to new user data A1: The sender MUST stop assigning new SSNs to new user data
provided by the upper layer for the affected streams and queue provided by the upper layer for the affected streams and queue
it. This is because it is not known whether the receiver of the it. This is because it is not known whether the receiver of the
request will accept or deny it and moreover, a lost request request will accept or deny it and moreover, a lost request
might cause an out-of-sequence error in a stream that the might cause an out-of-sequence error in a stream that the
receiver is not yet prepared to handle. receiver is not yet prepared to handle.
A2: The sender MUST assign the next stream reset request sequence A2: The sender MUST assign the next re-configuration request
number and MUST put it into the Stream Reset Request Sequence sequence number and MUST put it into the Re-configuration
Number field of the Outgoing SSN Reset Request Parameter. The Request Sequence Number field of the Outgoing SSN Reset Request
next stream reset request sequence number MUST then be Parameter. The next re-configuration request sequence number
incremented by 1. MUST then be incremented by 1.
A3: The Sender's Last Assigned TSN MUST be set to the next TSN the A3: The Sender's Last Assigned TSN MUST be set to the next TSN the
sender assigns minus 1. sender assigns minus 1.
A4: If this Outgoing SSN Reset Request Parameter is sent in response A4: If this Outgoing SSN Reset Request Parameter is sent in response
to an Incoming SSN Reset Request Parameter the Stream Numbers to an Incoming SSN Reset Request Parameter the Stream Numbers
MUST be copied from the Incoming SSN Reset Request Parameter to MUST be copied from the Incoming SSN Reset Request Parameter to
the Outgoing SSN Reset Request Parameter. The Stream Reset the Outgoing SSN Reset Request Parameter. The Re-configuration
Response Sequence Number of the Outgoing SSN Reset Request Response Sequence Number of the Outgoing SSN Reset Request
Parameter MUST be the Stream Reset Request Sequence Number of Parameter MUST be the Re-configuration Request Sequence Number
the Incoming SSN Reset Request Parameter. If this Outgoing SSN of the Incoming SSN Reset Request Parameter. If this Outgoing
Reset Request Parameter is sent at the request of the upper SSN Reset Request Parameter is sent at the request of the upper
layer and the sender requests all outgoing streams to be reset layer and the sender requests all outgoing streams to be reset
Stream Numbers SHOULD NOT be put into the Outgoing SSN Reset Stream Numbers SHOULD NOT be put into the Outgoing SSN Reset
Request Parameter. If the sender requests only some outgoing Request Parameter. If the sender requests only some outgoing
streams to be reset these Stream Numbers MUST be placed in the streams to be reset these Stream Numbers MUST be placed in the
Outgoing SSN Reset Request Parameter. Stream Reset Response Outgoing SSN Reset Request Parameter. Re-configuration Response
Sequence Number is the next expected Stream Reset Request Sequence Number is the next expected Re-configuration Request
Sequence Number of the peer minus 1. Sequence Number of the peer minus 1.
A5: The Outgoing SSN Reset Request Parameter MUST be put into a A5: The Outgoing SSN Reset Request Parameter MUST be put into a RE-
STREAM RESET Chunk. The Outgoing SSN Reset Request Parameter CONFIG Chunk. The Outgoing SSN Reset Request Parameter MAY be
MAY be put together with either an Incoming SSN Reset Request put together with either an Incoming SSN Reset Request Parameter
Parameter or an Stream Reset Response Parameter but not both. or an Re-configuration Response Parameter but not both. It MUST
It MUST NOT be put together with any other parameter as NOT be put together with any other parameter as described in
described in Section 3.1. Section 3.1.
A6: The STREAM RESET Chunk MUST be sent following the rules given in A6: The RE-CONFIG chunk MUST be sent following the rules given in
Section 5.1.1. Section 5.1.1.
5.1.3. Sender Side Procedures for the Incoming SSN Reset Request 5.1.3. Sender Side Procedures for the Incoming SSN Reset Request
Parameter Parameter
When an SCTP sender wants to reset the SSNs of some or all incoming When an SCTP sender wants to reset the SSNs of some or all incoming
streams it can send an Incoming SSN Reset Request Parameter provided streams it can send an Incoming SSN Reset Request Parameter provided
that the Stream Reset Timer is not running. The following steps must that the Re-configuration Timer is not running. The following steps
be followed: must be followed:
B1: The sender MUST assign the next stream reset request sequence B1: The sender MUST assign the next re-configuration request
number and MUST put it into the Stream Reset Request Sequence sequence number and MUST put it into the Re-configuration
Number field of the Incoming SSN Reset Request Parameter. After Request Sequence Number field of the Incoming SSN Reset Request
assigning it the next stream reset request sequence number MUST Parameter. After assigning it the next re-configuration request
be incremented by 1. sequence number MUST be incremented by 1.
B2: If the sender wants all incoming streams to be reset no Stream B2: If the sender wants all incoming streams to be reset no Stream
Numbers SHOULD be put into the Incoming SSN Reset Request Numbers SHOULD be put into the Incoming SSN Reset Request
Parameter. If the sender wants only some incoming streams to be Parameter. If the sender wants only some incoming streams to be
reset these Stream Numbers MUST be filled in the Incoming SSN reset these Stream Numbers MUST be filled in the Incoming SSN
Reset Request Parameter. Reset Request Parameter.
B3: The Incoming SSN Reset Request Parameter MUST be put into a B3: The Incoming SSN Reset Request Parameter MUST be put into a RE-
STREAM RESET Chunk. It MAY be put together with an Outgoing SSN CONFIG Chunk. It MAY be put together with an Outgoing SSN Reset
Reset Request Parameter but MUST NOT be put together with any Request Parameter but MUST NOT be put together with any other
other parameter. parameter.
B4: The STREAM RESET Chunk MUST be sent following the rules given in B4: The RE-CONFIG chunk MUST be sent following the rules given in
Section 5.1.1. Section 5.1.1.
When sending a Incoming SSN Reset Request their is a potential that When sending a Incoming SSN Reset Request their is a potential that
the peer has just reset or is in the process of resetting the same the peer has just reset or is in the process of resetting the same
streams via an Outgoing SSN Reset Request. This collision scenario streams via an Outgoing SSN Reset Request. This collision scenario
is discussed in Section 5.2.3. is discussed in Section 5.2.3.
5.1.4. Sender Side Procedures for the SSN/TSN Reset Request Parameter 5.1.4. Sender Side Procedures for the SSN/TSN Reset Request Parameter
When an SCTP sender wants to reset the SSNs and TSNs it can send an When an SCTP sender wants to reset the SSNs and TSNs it can send an
SSN/TSN Reset Request Parameter provided that the Stream Reset Timer SSN/TSN Reset Request Parameter provided that the Re-configuration
is not running. The following steps must be followed: Timer is not running. The following steps must be followed:
C1: The sender MUST assign the next stream reset request sequence C1: The sender MUST assign the next re-configuration request
number and put it into the Stream Reset Request Sequence Number sequence number and put it into the Re-configuration Request
field of the SSN/TSN Reset Request Parameter. After assigning Sequence Number field of the SSN/TSN Reset Request Parameter.
it the next stream reset request sequence number MUST be After assigning it the next re-configuration request sequence
incremented by 1. number MUST be incremented by 1.
C2: The sender MUST queue any user data suspending any new C2: The sender MUST queue any user data suspending any new
transmissions and TSN assignment until the reset procedure is transmissions and TSN assignment until the reset procedure is
finished by the peer either acknowledging or denying the finished by the peer either acknowledging or denying the
request. request.
C3: The SSN/TSN Reset Request Parameter MUST be put into a STREAM C3: The SSN/TSN Reset Request Parameter MUST be put into a RE-CONFIG
RESET Chunk. There MUST NOT be any other parameter in this chunk. There MUST NOT be any other parameter in this chunk.
chunk.
C4: The STREAM RESET Chunk MUST be sent following the rules given in C4: The RE-CONFIG chunk MUST be sent following the rules given in
Section 5.1.1. Section 5.1.1.
Only one SSN/TSN Reset Request SHOULD be sent within 30 seconds, Only one SSN/TSN Reset Request SHOULD be sent within 30 seconds,
which is considered a maximum segment lifetime, the IP MSL. which is considered a maximum segment lifetime, the IP MSL.
5.1.5. Sender Side Procedures for the Stream Reset Response Parameter 5.1.5. Sender Side Procedures for the Re-configuration Response
Parameter
When an implementation receives a reset request parameter it must When an implementation receives a reset request parameter it must
respond with a Stream Reset Response Parameter in the following respond with a Re-configuration Response Parameter in the following
manner: manner:
D1: The Stream Reset Request Sequence number of the incoming request D1: The Re-configuration Request Sequence number of the incoming
MUST be copied to the Stream Reset Response Sequence Number request MUST be copied to the Re-configuration Response Sequence
field of the Stream Reset Response Parameter. Number field of the Re-configuration Response Parameter.
D2: The result of the processing of the incoming request according D2: The result of the processing of the incoming request according
to Table 3 MUST be placed in the Result field of the Stream to Table 3 MUST be placed in the Result field of the Re-
Reset Response Parameter. configuration Response Parameter.
D3: If the incoming request is an SSN/TSN reset request, the D3: If the incoming request is an SSN/TSN reset request, the
Sender's next TSN field MUST be filled with the next TSN the Sender's next TSN field MUST be filled with the next TSN the
sender of this Stream Reset Response Parameter will assign. For sender of this Re-configuration Response Parameter will assign.
other requests the Sender's next TSN field, which is optional, For other requests the Sender's next TSN field, which is
MUST NOT be used. optional, MUST NOT be used.
D4: If the incoming request is an SSN/TSN reset request, the D4: If the incoming request is an SSN/TSN reset request, the
Receiver's next TSN field MUST be filled with a TSN such that Receiver's next TSN field MUST be filled with a TSN such that
the sender of the Stream Reset Response Parameter can be sure it the sender of the Re-configuration Response Parameter can be
can discard received DATA chunks with smaller TSNs. The value sure it can discard received DATA chunks with smaller TSNs. The
SHOULD be the smallest TSN not acknowledged by the receiver of value SHOULD be the smallest TSN not acknowledged by the
the request plus 2^31. For other requests the Receiver's next receiver of the request plus 2^31. For other requests the
TSN field, which is optional, MUST NOT be used. Receiver's next TSN field, which is optional, MUST NOT be used.
5.1.6. Sender Side Procedures for the Add Outgoing Streams Request 5.1.6. Sender Side Procedures for the Add Outgoing Streams Request
Parameter Parameter
When an SCTP sender wants to increase the number of outbound streams When an SCTP sender wants to increase the number of outbound streams
to which it is able to send, it may add an Add Outgoing Streams to which it is able to send, it may add an Add Outgoing Streams
Request parameter to the STREAM RESET chunk. Upon sending the Request parameter to the RE-CONFIG chunk. Upon sending the request
request the sender MUST await a positive acknowledgment (Success) the sender MUST await a positive acknowledgment (Success) before
before using any additional stream added by this request. Note that using any additional stream added by this request. Note that new
new streams are added adjacent to the previous streams with no gaps. streams are added adjacent to the previous streams with no gaps.
This means that if a request is made to add 2 streams to an This means that if a request is made to add 2 streams to an
association that has already 5 (0-4) then the new streams, upon association that has already 5 (0-4) then the new streams, upon
successful completion, are streams 5 and 6. A new stream MUST use successful completion, are streams 5 and 6. A new stream MUST use
the stream sequence number 0 for its first ordered message. the stream sequence number 0 for its first ordered message.
5.2. Receiver Side Procedures 5.2. Receiver Side Procedures
5.2.1. Receiver Side Procedures for the Stream Reset Chunk 5.2.1. Receiver Side Procedures for the RE-CONFIG Chunk
Upon reception of a Stream Reset Chunk each parameter within it Upon reception of a RE-CONFIG chunk each parameter within it SHOULD
SHOULD be processed. If multiple parameters have to be returned, be processed. If multiple parameters have to be returned, they MUST
they MUST be put into one STREAM RESET chunk. If the received STREAM be put into one RE_CONFIG chunk. If the received RE-CONFIG chunk
RESET chunk contains at least one request parameter, a SACK chunk contains at least one request parameter, a SACK chunk SHOULD be sent
SHOULD be sent back and MAY be bundled with the STREAM RESET chunk. back and MAY be bundled with the RE-CONFIG chunk. If the received
If the received STREAM RESET chunk contains at least one request and RE-CONFIG chunk contains at least one request and based on the
based on the analysis of the Stream Reset Request Sequence Numbers analysis of the Re-configuration Request Sequence Numbers this is the
this is the last received STREAM RESET chunk (i.e. a retransmission), last received RE-CONFIG chunk (i.e. a retransmission), the same RE-
the same STREAM RESET chunk MUST to be sent back in response as was CONFIG chunk MUST to be sent back in response as was earlier.
earlier.
The decision to deny a stream reset request is an administrative The decision to deny a re-configuration request is an administrative
decision and may be user configurable even after the association has decision and may be user configurable even after the association has
formed. If for whatever reason the endpoint does not wish to process formed. If for whatever reason the endpoint does not wish to process
a received request parameter it MUST send a corresponding response a received request parameter it MUST send a corresponding response
parameter as described in Section 5.1.5 with an appropriate Result parameter as described in Section 5.1.5 with an appropriate Result
field. field.
Implementation Note: A SACK is recommended to be bundled with any Implementation Note: A SACK is recommended to be bundled with any re-
stream reset response so that any retransmission processing that configuration response so that any retransmission processing that
needs to occur can be expedited. A SACK chunk is not required for needs to occur can be expedited. A SACK chunk is not required for
this feature to work, but it will in effect help minimize the delay this feature to work, but it will in effect help minimize the delay
in completing a stream reset operation in the face of any data loss. in completing a re-configuration operation in the face of any data
loss.
5.2.2. Receiver Side Procedures for the Outgoing SSN Reset Request 5.2.2. Receiver Side Procedures for the Outgoing SSN Reset Request
Parameter Parameter
In the case that the endpoint is willing to perform a stream reset In the case that the endpoint is willing to perform a stream reset
the following steps must be followed: the following steps must be followed:
E1: If the Stream Reset Timer is running for the Stream Reset E1: If the Re-configuration Timer is running for the Re-
Request Sequence Number indicated in the Stream Reset Response configuration Request Sequence Number indicated in the Re-
Sequence Number field, the Stream Reset Request Sequence Number configuration Response Sequence Number field, the Re-
MUST be marked as acknowledged. If all Stream Reset Request configuration Request Sequence Number MUST be marked as
Sequence Numbers the Stream Reset Timer is running for are acknowledged. If all Re-configuration Request Sequence Numbers
acknowledged, the Stream Reset Timer MUST be stopped. the Re-configuration Timer is running for are acknowledged, the
Re-configuration Timer MUST be stopped.
E2: If the Sender's Last Assigned TSN number is greater than the E2: If the Sender's Last Assigned TSN number is greater than the
cumulative acknowledgment point, then the endpoint MUST enter cumulative acknowledgment point, then the endpoint MUST enter
"deferred reset processing". In this mode, any data arriving "deferred reset processing". In this mode, any data arriving
with a TSN number larger than the 'senders last assigned TSN' with a TSN number larger than the 'senders last assigned TSN'
for the affected stream(s) MUST be queued locally and held until for the affected stream(s) MUST be queued locally and held until
the Cumulative Acknowledgment point reaches the 'senders last the Cumulative Acknowledgment point reaches the 'senders last
assigned TSN number'. When the Cumulative Acknowledgment point assigned TSN number'. When the Cumulative Acknowledgment point
reaches the last assigned TSN number then proceed to the next reaches the last assigned TSN number then proceed to the next
step. If the endpoint enters "deferred reset processing", it step. If the endpoint enters "deferred reset processing", it
MUST put a Stream Reset Response Parameter into a STREAM RESET MUST put a Re-configuration Response Parameter into a RE-CONFIG
chunk indicating 'In progress' and MUST send the STREAM RESET chunk indicating 'In progress' and MUST send the RE-CONFIG
chunk. chunk.
E3: If no Stream Numbers are listed in the parameter, then all E3: If no Stream Numbers are listed in the parameter, then all
incoming streams MUST be reset to 0 as the next expected stream incoming streams MUST be reset to 0 as the next expected stream
sequence number. If specific Stream Numbers are listed, then sequence number. If specific Stream Numbers are listed, then
only these specific streams MUST be reset to 0 and all other only these specific streams MUST be reset to 0 and all other
non-listed stream sequence numbers remain unchanged. non-listed stream sequence numbers remain unchanged.
E4: Any queued TSN's (queued at step E2) MUST now be released and E4: Any queued TSN's (queued at step E2) MUST now be released and
processed normally. processed normally.
E5: A Stream Reset Response Parameter MUST be put into a STREAM E5: A Re-configuration Response Parameter MUST be put into a RE-
RESET chunk indicating successful processing. CONFIG chunk indicating successful processing.
E6: The STREAM RESET chunk MUST be sent after the incoming STREAM E6: The RE-CONFIG chunk MUST be sent after the incoming RE-CONFIG
RESET chunk is processed completely. chunk is processed completely.
5.2.3. Receiver Side Procedures for the Incoming SSN Reset Request 5.2.3. Receiver Side Procedures for the Incoming SSN Reset Request
Parameter Parameter
In the case that the endpoint is willing to perform a stream reset In the case that the endpoint is willing to perform a stream reset
the following steps must be followed: the following steps must be followed:
F1: An Outgoing SSN Reset Request Parameter MUST be put into an F1: An Outgoing SSN Reset Request Parameter MUST be put into an RE-
STREAM RESET chunk according to Section 5.1.2. CONFIG chunk according to Section 5.1.2.
F2: The STREAM RESET chunk MUST be sent after the incoming STREAM F2: The RE-CONFIG chunk MUST be sent after the incoming RE-CONFIG
RESET chunk is processed completely. chunk is processed completely.
If the endpoint is un-willing to perform the stream reset it MUST If the endpoint is un-willing to perform the stream reset it MUST
send a Stream Reset Response Parameter with the appropriate error set send a Re-configuration Response Parameter with the appropriate error
to "Denied". set to "Denied".
When a peer endpoint requests a Incoming SSN Reset Request it is When a peer endpoint requests a Incoming SSN Reset Request it is
possible that the local endpoint has just sent an Outgoing SSN Reset possible that the local endpoint has just sent an Outgoing SSN Reset
Request on the same stream and has not yet received a response. In Request on the same stream and has not yet received a response. In
such a case the local endpoint MUST do the following: such a case the local endpoint MUST do the following:
1) If the stream reset overlaps the outstanding request completely 1) If the stream reset overlaps the outstanding request completely
respond to the requestor with a acknowledgment indicating that respond to the requestor with a acknowledgment indicating that
there was 'Nothing to do'. there was 'Nothing to do'.
2) Otherwise process the stream reset request normally responding to 2) Otherwise process the re-configuration request normally responding
the requestor with a acknowledgment. to the requestor with a acknowledgment.
It is also possible that the Incoming request will arrive after the It is also possible that the Incoming request will arrive after the
Outgoing SSN Reset Request just completed. In such a case all of the Outgoing SSN Reset Request just completed. In such a case all of the
streams being requested will be already set to 0. If so, the local streams being requested will be already set to 0. If so, the local
endpoint SHOULD send back a Stream Reset Response with the success endpoint SHOULD send back a Re-configuration Response with the
code "Nothing to do". success code "Nothing to do".
Note that in either race condition the local endpoint could Note that in either race condition the local endpoint could
optionally also perform the reset. This would result in streams that optionally also perform the reset. This would result in streams that
are already at sequence 0 being reset again to 0 which would cause no are already at sequence 0 being reset again to 0 which would cause no
harm to the application but will add an extra message to the network. harm to the application but will add an extra message to the network.
5.2.4. Receiver Side Procedures for the SSN/TSN Reset Request Parameter 5.2.4. Receiver Side Procedures for the SSN/TSN Reset Request Parameter
In the case that the endpoint is willing to perform an SSN/TSN reset In the case that the endpoint is willing to perform an SSN/TSN reset
the following steps must be followed: the following steps must be followed:
skipping to change at page 19, line 31 skipping to change at page 19, line 31
cumulative TSN ACK of Sender's next TSN minus 1 was received cumulative TSN ACK of Sender's next TSN minus 1 was received
MUST be performed. MUST be performed.
G4: The same processing as if a FWD-TSN chunk as defined in G4: The same processing as if a FWD-TSN chunk as defined in
[RFC3758] with all streams affected and a new cumulative TSN ACK [RFC3758] with all streams affected and a new cumulative TSN ACK
of Receiver's next TSN minus 1 was received MUST be performed. of Receiver's next TSN minus 1 was received MUST be performed.
G5: The next expected and outgoing stream sequence numbers MUST be G5: The next expected and outgoing stream sequence numbers MUST be
reset to 0 for all incoming and outgoing streams. reset to 0 for all incoming and outgoing streams.
G6: A Stream Reset Response Parameter MUST be put into a STREAM G6: A Re-configuration Response Parameter MUST be put into a RE-
RESET chunk indicating successful processing. CONFIG chunk indicating successful processing.
G7: The STREAM RESET chunk MUST be sent after the incoming STREAM G7: The RE-CONFIG chunk MUST be sent after the incoming RE-CONFIG
RESET chunk is processed completely. chunk is processed completely.
5.2.5. Receiver Side Procedures for the Add Outgoing Streams Request 5.2.5. Receiver Side Procedures for the Add Outgoing Streams Request
Parameter Parameter
When an SCTP endpoint receives a stream reset request adding When an SCTP endpoint receives a re-configuration request adding
additional streams, it MUST send a response parameter either additional streams, it MUST send a response parameter either
acknowledging or denying the request. If the response is successful acknowledging or denying the request. If the response is successful
the receiver MUST add the requested number of inbound streams to the the receiver MUST add the requested number of inbound streams to the
association, initializing the next expected stream sequence number to association, initializing the next expected stream sequence number to
be 0. be 0.
5.2.6. Receiver Side Procedures for the Stream Reset Response Parameter 5.2.6. Receiver Side Procedures for the Re-configuration Response
Parameter
On receipt of a Stream Reset Response Parameter the following must be On receipt of a Re-configuration Response Parameter the following
performed: must be performed:
H1: If the Stream Reset Timer is running for the Stream Reset H1: If the Re-confguration Timer is running for the Re-configuration
Request Sequence Number indicated in the Stream Reset Response Request Sequence Number indicated in the Re-configuration
Sequence Number field, the Stream Reset Request Sequence Number Response Sequence Number field, the Re-configuration Request
MUST be marked as acknowledged. If all Stream Reset Request Sequence Number MUST be marked as acknowledged. If all Re-
Sequence Numbers the Stream Reset Timer is running for are configuration Request Sequence Numbers the Re-configuration
acknowledged, the Stream Reset Timer MUST be stopped. If the Timer is running for are acknowledged, the Re-configuration
timer was not running for the Stream Reset Request Sequence Timer MUST be stopped. If the timer was not running for the Re-
Number, the processing of the Stream Reset Response Parameter is configuration Request Sequence Number, the processing of the Re-
complete. configuration Response Parameter is complete.
H2: If the Result field indicates 'In progress', the timer for the H2: If the Result field indicates 'In progress', the timer for the
Stream Reset Request Sequence Number is started again. If the Re-configuration Request Sequence Number is started again. If
timer runs off, the Stream Reset Chunk MUST be retransmitted but the timer runs off, the RE-CONFIG chunk MUST be retransmitted
the corresponding error counters MUST NOT be incremented. but the corresponding error counters MUST NOT be incremented.
H3: If the Result field does not indicate successful processing the H3: If the Result field does not indicate successful processing the
processing of this response is complete. processing of this response is complete.
H4: If the request was an Outgoing SSN Reset Request the affected H4: If the request was an Outgoing SSN Reset Request the affected
streams MUST now be reset and all queued data should be streams MUST now be reset and all queued data should be
processed now and assigning of stream sequence numbers is processed now and assigning of stream sequence numbers is
allowed again. allowed again.
H5: If the request was an SSN/TSN Reset Request new data MUST be H5: If the request was an SSN/TSN Reset Request new data MUST be
skipping to change at page 20, line 44 skipping to change at page 20, line 44
H6: If the request was to add outgoing streams, the endpoint MUST H6: If the request was to add outgoing streams, the endpoint MUST
add the additional streams to the association. Note that an add the additional streams to the association. Note that an
implementation may allocate the memory at the time of the implementation may allocate the memory at the time of the
request, but it MUST NOT use the streams until the peer has request, but it MUST NOT use the streams until the peer has
responded with a positive acknowledgment. responded with a positive acknowledgment.
6. Socket API Considerations 6. Socket API Considerations
This section describes how the socket API defined in This section describes how the socket API defined in
[I-D.ietf-tsvwg-sctpsocket] needs to be extended to make the features [I-D.ietf-tsvwg-sctpsocket] needs to be extended to make the features
of SCTP stream reset available to the application. of SCTP re-configuration available to the application.
Please note that this section is informational only. Please note that this section is informational only.
6.1. Events 6.1. Events
When the SCTP_ASSOC_CHANGE notification is delivered and both peers When the SCTP_ASSOC_CHANGE notification is delivered and both peers
support the extension described in this document, support the extension described in this document,
SCTP_ASSOC_SUPPORTS_STREAM_RESET should be listed in the sac_info SCTP_ASSOC_SUPPORTS_RE_CONFIG should be listed in the sac_info field.
field.
The union sctp_notification {} is extended to contain three new The union sctp_notification {} is extended to contain three new
fields: sn_strreset_event, sn_assocreset_event, and fields: sn_strreset_event, sn_assocreset_event, and
sn_strchange_event: sn_strchange_event:
union sctp_notification { union sctp_notification {
struct { struct {
uint16_t sn_type; uint16_t sn_type;
uint16_t sn_flags; uint16_t sn_flags;
uint32_t sn_length; uint32_t sn_length;
skipping to change at page 24, line 26 skipping to change at page 24, line 26
sockets, this field is ignored. sockets, this field is ignored.
strchange_instrms: The number of streams that the peer is allowed to strchange_instrms: The number of streams that the peer is allowed to
use outbound. use outbound.
strchange_outstrms: The number of streams that the endpoint is strchange_outstrms: The number of streams that the endpoint is
allowed to use outbound. allowed to use outbound.
6.2. Event Subscription 6.2. Event Subscription
There are two methods defined in the SCTP socket API to subscribe to Subscribing to events as described in [I-D.ietf-tsvwg-sctpsocket]
events. The original method defined was an events structure with the uses a setsockopt() call with the SCTP_EVENT socket option. This
socket option SCTP_EVENTS. Some implementations may have already option takes the following structure that specifies the association,
expanded their data structure for this API to include the stream the event type (using the same value found in the event type field)
reset subscriptions. The new API is to use a setsockopt() call with and an on/off boolean.
the SCTP_SET_EVENT socket option. This option takes a structure that
defines the association, the event type (using the same value found
in the event type field) and an on/off boolean. This newer API is
the preferred method but we define both methods for compatibility.
For some implementations the structure now takes on the form:
struct sctp_event_subscribe {
uint8_t sctp_data_io_event;
uint8_t sctp_association_event;
uint8_t sctp_address_event;
uint8_t sctp_send_failure_event;
uint8_t sctp_peer_error_event;
uint8_t sctp_shutdown_event;
uint8_t sctp_partial_delivery_event;
uint8_t sctp_adaptation_layer_event;
uint8_t sctp_authentication_event;
uint8_t sctp_sender_dry_event;
uint8_t sctp_stream_reset_event;
uint8_t sctp_assoc_reset_event;
uint8_t sctp_stream_change_event;
};
For those implementations that support this method simply putting a 1
or 0 in the sctp_stream_reset_event and setting the SCTP_EVENTS
socket option will work. However not all implementations support
this method.
The preferred method is to use the SCTP_SET_EVENT socket option and
fill in the structure sctp_set_event structure.
struct sctp_set_event { struct sctp_event {
sctp_assoc_t se_assoc_id; sctp_assoc_t se_assoc_id;
uint16_t se_type; uint16_t se_type;
uint8_t se_on; uint8_t se_on;
}; };
Using this method, the user fills in the se_type with the same value The user fills in the se_type with the same value found in the
found in strreset_type field i.e. SCTP_STREAM_RESET_EVENT. The user strreset_type field i.e. SCTP_STREAM_RESET_EVENT. The user will
will also fill in the se_assoc_id field with either the association also fill in the se_assoc_id field with either the association to set
to set this event on (this field is ignored for one-to-one style this event on (this field is ignored for one-to-one style sockets) or
sockets) or one of the reserved constant values defined in the socket one of the reserved constant values defined in
API document. Finally the se_on field is set with a 1 to enable the [I-D.ietf-tsvwg-sctpsocket]. Finally the se_on field is set with a 1
event or a 0 to disable the event. to enable the event or a 0 to disable the event.
6.3. Socket Options 6.3. Socket Options
The following table describes the new socket options which make the The following table describes the new socket options which make the
SCTP stream reset features accessible to the user. They all use re-configuration features accessible to the user. They all use
IPPROTO_SCTP as their level. IPPROTO_SCTP as their level.
+--------------------------+---------------------------+-----+-----+ +--------------------------+---------------------------+-----+-----+
| option name | data type | get | set | | option name | data type | get | set |
+--------------------------+---------------------------+-----+-----+ +--------------------------+---------------------------+-----+-----+
| SCTP_ENABLE_STREAM_RESET | struct sctp_assoc_value | X | X | | SCTP_ENABLE_STREAM_RESET | struct sctp_assoc_value | X | X |
| SCTP_RESET_STREAMS | struct sctp_reset_streams | | X | | SCTP_RESET_STREAMS | struct sctp_reset_streams | | X |
| SCTP_RESET_ASSOC | sctp_assoc_t | | X | | SCTP_RESET_ASSOC | sctp_assoc_t | | X |
| SCTP_ADD_OUT_STREAMS | struct sctp_assoc_value | | X | | SCTP_ADD_OUT_STREAMS | struct sctp_assoc_value | | X |
+--------------------------+---------------------------+-----+-----+ +--------------------------+---------------------------+-----+-----+
Table 5 Table 5
6.3.1. Enable/Disable Stream Reset (SCTP_ENABLE_STREAM_RESET) 6.3.1. Enable/Disable Stream Reset (SCTP_ENABLE_STREAM_RESET)
This option allows a user to control whether the SCTP implementation This option allows a user to control whether the SCTP implementation
processes or denies incoming requests in STREAM_RESET chunks. processes or denies incoming requests in STREAM_RESET chunks.
The default is to deny incoming requests. The default is to deny all incoming requests.
To set or get this option the user fills in the following structure: To set or get this option the user fills in the following structure:
struct sctp_assoc_value { struct sctp_assoc_value {
sctp_assoc_t assoc_id; sctp_assoc_t assoc_id;
uint32_t assoc_value; uint32_t assoc_value;
}; };
assoc_id: This parameter is ignored for one-to-one style sockets. assoc_id: This parameter is ignored for one-to-one style sockets.
For one-to-many style sockets this parameter indicates which For one-to-many style sockets this parameter indicates which
association the user is performing an action upon. association the user is performing an action upon.
assoc_value: It is formed from the bitwise OR of one or more of the assoc_value: It is formed from the bitwise OR of one or more of the
following currently defined flags: following currently defined flags:
SCTP_DENY_RESET_IN_STREAM_REQ: Deny received Incoming SSN Reset SCTP_ENABLE_RESET_IN_STREAM_REQ: Process received Incoming SSN
Requests if this flag is set, process it if not. Reset Requests if this flag is set, deny them if not.
SCTP_DENY_RESET_OUT_STREAM_REQ: Deny received Outgoing SSN Reset SCTP_ENABLE_RESET_OUT_STREAM_REQ: Process received Outgoing SSN
Requests if this flag is set, process it if not. Reset Requests if this flag is set, deny them if not.
SCTP_DENY_RESET_ASSOC_REQ: Deny received SSN/TSN Reset Requests SCTP_ENABLE_RESET_ASSOC_REQ: Process received SSN/TSN Reset
if this flag is set, process it if not. Requests if this flag is set, deny them if not.
SCTP_DENY_CHANGE_ASSOC_REQ: Deny received Add Outgoing Streams SCTP_ENABLE_CHANGE_ASSOC_REQ: Process received Add Outgoing
Requests if this flag is set, process it if not. Streams Requests if this flag is set, deny them if not.
The default value is SCTP_DENY_IN_STREAM_RESET| The default value is !(SCTP_ENABLE_IN_STREAM_RESET|
SCTP_DENY_OUT_STREAM_RESET|SCTP_DENY_ASSOC_RESET| SCTP_ENABLE_OUT_STREAM_RESET|SCTP_ENABLE_ASSOC_RESET|
SCTP_DENY_ASSOC_CHANGE. SCTP_ENABLE_ASSOC_CHANGE).
Please note that using the option does not have any impact on Please note that using the option does not have any impact on
subscribing to any related events. subscribing to any related events.
6.3.2. Reset Incoming and/or Outgoing Streams (SCTP_RESET_STREAMS) 6.3.2. Reset Incoming and/or Outgoing Streams (SCTP_RESET_STREAMS)
This option allows the user to request the reset of incoming and/or This option allows the user to request the reset of incoming and/or
outgoing streams. outgoing streams.
To set or get this option the user fills in the following structure: To set or get this option the user fills in the following structure:
skipping to change at page 28, line 22 skipping to change at page 27, line 36
sinit_max_instreams field in the struct sctp_initmsg{} when issuing sinit_max_instreams field in the struct sctp_initmsg{} when issuing
an SCTP_INIT socket option, as defined in an SCTP_INIT socket option, as defined in
[I-D.ietf-tsvwg-sctpsocket]. An incoming request asking for more [I-D.ietf-tsvwg-sctpsocket]. An incoming request asking for more
streams than allowed will be denied. streams than allowed will be denied.
7. Security Considerations 7. Security Considerations
The SCTP socket API as described in [I-D.ietf-tsvwg-sctpsocket] The SCTP socket API as described in [I-D.ietf-tsvwg-sctpsocket]
exposes the sequence numbers of received DATA chunks to the exposes the sequence numbers of received DATA chunks to the
application. An application might expect them to be monotonically application. An application might expect them to be monotonically
increasing. When using the stream reset extension this might no increasing. When using the re-configuration extension this might no
longer be true. Therefore the application must enable this extension longer be true. Therefore the application must enable this extension
explicitly before it is used. In addition, application must explicitly before it is used. In addition, application must
subscribe explicitly to notifications related to the stream reset subscribe explicitly to notifications related to the re-configuration
extension before receiving them. extension before receiving them.
SCTP associations are protected against blind attackers by using the SCTP associations are protected against blind attackers by using the
verification tags. This is still valid when using the stream reset verification tags. This is still valid when using the re-
extension. Therefore this extension does not add any additional configuration extension. Therefore this extension does not add any
security risk to SCTP in relation to blind attackers. additional security risk to SCTP in relation to blind attackers.
When the both sequence numbers are reset, the maximum segment When the both sequence numbers are reset, the maximum segment
lifetime is used to avoid the wrap-around for the TSN. lifetime is used to avoid the wrap-around for the TSN.
8. IANA Considerations 8. IANA Considerations
[NOTE to RFC-Editor: [NOTE to RFC-Editor:
"RFCXXXX" is to be replaced by the RFC number you assign this "RFCXXXX" is to be replaced by the RFC number you assign this
document. document.
skipping to change at page 29, line 23 skipping to change at page 28, line 37
A chunk type has to be assigned by IANA. It is suggested to use the A chunk type has to be assigned by IANA. It is suggested to use the
values given in Table 1. IANA should assign this value from the pool values given in Table 1. IANA should assign this value from the pool
of chunks with the upper two bits set to '10'. of chunks with the upper two bits set to '10'.
This requires an additional line in the "CHUNK TYPES" table for SCTP: This requires an additional line in the "CHUNK TYPES" table for SCTP:
CHUNK TYPES CHUNK TYPES
ID Value Chunk Type Reference ID Value Chunk Type Reference
----- ---------- --------- ----- ---------- ---------
130 Stream Reset Chunk (STREAM_RESET) [RFCXXXX] 130 Re-configuration Chunk (RE-CONFIG) [RFCXXXX]
The registration table as defined in The registration table as defined in [RFC6096] for the chunk flags of
[I-D.ietf-tsvwg-sctp-chunk-flags] for the chunk flags of this chunk this chunk type is empty.
type is empty.
8.2. Five New Parameter Types 8.2. Five New Parameter Types
IANA is requested to create a new sub-registry, "STREAM RESET Chunk IANA is requested to create a new sub-registry, "RE-CONFIG Chunk
Parameter Types" with the following initial contents, taken from Parameter Types" with the following initial contents, taken from
Table 2 of this document: Table 2 of this document:
--STREAM RESET Chunk Parameter Types --RE-CONFIG Chunk Parameter Types
Chunk Parameter Type Value Chunk Parameter Type Value
-------------------- ---------- -------------------- ----------
Outgoing SSN Reset Request Parameter 13 (0x000d) Outgoing SSN Reset Request Parameter 13 (0x000d)
Incoming SSN Reset Request Parameter 14 (0x000e) Incoming SSN Reset Request Parameter 14 (0x000e)
SSN/TSN Reset Request Parameter 15 (0x000f) SSN/TSN Reset Request Parameter 15 (0x000f)
Stream Reset Response Parameter 16 (0x0010) Re-configuration Response Parameter 16 (0x0010)
Add Outgoing Streams Request Parameter 17 (0x0011) Add Outgoing Streams Request Parameter 17 (0x0011)
9. Acknowledgments 9. Acknowledgments
The authors wish to thank Paul Aitken, Gorry Fairhurst, Tom Petch, The authors wish to thank Paul Aitken, Gorry Fairhurst, Tom Petch,
Kacheong Poon, Irene Ruengeler, Robin Seggelmann, and Vlad Yasevich Kacheong Poon, Irene Ruengeler, Robin Seggelmann, and Vlad Yasevich
for there invaluable comments. for there invaluable comments.
Appendix A. Examples of the Stream Reset procedures 10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3758] Stewart, R., Ramalho, M., Xie, Q., Tuexen, M., and P.
Conrad, "Stream Control Transmission Protocol (SCTP)
Partial Reliability Extension", RFC 3758, May 2004.
[RFC4960] Stewart, R., "Stream Control Transmission Protocol",
RFC 4960, September 2007.
[RFC5061] Stewart, R., Xie, Q., Tuexen, M., Maruyama, S., and M.
Kozuka, "Stream Control Transmission Protocol (SCTP)
Dynamic Address Reconfiguration", RFC 5061,
September 2007.
[RFC6096] Tuexen, M. and R. Stewart, "Stream Control Transmission
Protocol (SCTP) Chunk Flags Registration", RFC 6096,
January 2011.
10.2. Informative References
[I-D.ietf-tsvwg-sctpsocket]
Stewart, R., Tuexen, M., Poon, K., Lei, P., and V.
Yasevich, "Sockets API Extensions for Stream Control
Transmission Protocol (SCTP)",
draft-ietf-tsvwg-sctpsocket-30 (work in progress),
June 2011.
Appendix A. Examples of the Re-configuration procedures
Please note that this appendix is informational only. Please note that this appendix is informational only.
The following message flows between an Endpoint A and an Endpoint Z The following message flows between an Endpoint A and an Endpoint Z
illustrate the described procedures. The time progresses in downward illustrate the described procedures. The time progresses in downward
direction. direction.
The following example illustrates an Endpoint A resetting stream 1 The following example illustrates an Endpoint A resetting stream 1
and 2 for just its outgoing streams. and 2 for just its outgoing streams.
E-A E-Z E-A E-Z
----------[STR_RESET(OUT-REQ:X/1,2)]----------> ----------[RE-CONFIG(OUT-REQ:X/1,2)]---------->
<-------------[STR_RESET(RESP:X)]-------------- <-------------[RE-CONFIG(RESP:X)]--------------
The following example illustrates an Endpoint A resetting stream 1 The following example illustrates an Endpoint A resetting stream 1
and 2 for just its incoming streams. and 2 for just its incoming streams.
E-A E-Z E-A E-Z
-----------[STR_RESET(IN-REQ:X/1,2)]----------> -----------[RE-CONFIG(IN-REQ:X/1,2)]---------->
<--------[STR_RESET(OUT-REQ:Y,X/1,2)]---------- <--------[RE-CONFIG(OUT-REQ:Y,X/1,2)]----------
-------------[STR_RESET(RESP:Y)]--------------> -------------[RE-CONFIG(RESP:Y)]-------------->
The following example illustrates an Endpoint A resetting all streams The following example illustrates an Endpoint A resetting all streams
in both directions. in both directions.
E-A E-Z E-A E-Z
-----[STR_RESET(OUT-REQ:X,Y-1)|IN-REQ:X+1]----> -----[RE-CONFIG(OUT-REQ:X,Y-1)|IN-REQ:X+1]---->
<------[STR_RESET(RESP:X|OUT-REQ:Y,X+1)]------- <------[RE-CONFIG(RESP:X|OUT-REQ:Y,X+1)]-------
-------------[STR_RESET(RESP:Y)]--------------> -------------[RE-CONFIG(RESP:Y)]-------------->
The following example illustrates an Endpoint A requesting the The following example illustrates an Endpoint A requesting the
streams and TSNs be reset. At the completion E-A has the new sending streams and TSNs be reset. At the completion E-A has the new sending
TSN (selected by the peer) of B and E-Z has the new sending TSN of A TSN (selected by the peer) of B and E-Z has the new sending TSN of A
(also selected by the peer). (also selected by the peer).
E-A E-Z E-A E-Z
------------[STR_RESET(TSN-REQ:X)]------------> ------------[RE-CONFIG(TSN-REQ:X)]------------>
<-----[STR_RESET(RESP:X/S-TSN=A, R-TSN=B)]----- <-----[RE-CONFIG(RESP:X/S-TSN=A, R-TSN=B)]-----
The following example illustrates an Endpoint A requesting to add 3 The following example illustrates an Endpoint A requesting to add 3
additional outgoing streams. additional outgoing streams.
E-A E-Z E-A E-Z
--------[STR_RESET(ADD_OUT_STRMS:X/3)]--------> --------[RE-CONFIG(ADD_OUT_STRMS:X/3)]-------->
<-------------[STR_RESET(RESP:X)]-------------- <-------------[RE-CONFIG(RESP:X)]--------------
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3758] Stewart, R., Ramalho, M., Xie, Q., Tuexen, M., and P.
Conrad, "Stream Control Transmission Protocol (SCTP)
Partial Reliability Extension", RFC 3758, May 2004.
[RFC4960] Stewart, R., "Stream Control Transmission Protocol",
RFC 4960, September 2007.
[RFC5061] Stewart, R., Xie, Q., Tuexen, M., Maruyama, S., and M.
Kozuka, "Stream Control Transmission Protocol (SCTP)
Dynamic Address Reconfiguration", RFC 5061,
September 2007.
[I-D.ietf-tsvwg-sctp-chunk-flags]
Tuexen, M. and R. Stewart, "Stream Control Transmission
Protocol (SCTP) Chunk Flags Registration",
draft-ietf-tsvwg-sctp-chunk-flags-02 (work in progress),
October 2010.
10.2. Informative References
[I-D.ietf-tsvwg-sctpsocket]
Stewart, R., Poon, K., Tuexen, M., Yasevich, V., and P.
Lei, "Sockets API Extensions for Stream Control
Transmission Protocol (SCTP)",
draft-ietf-tsvwg-sctpsocket-24 (work in progress),
October 2010.
Authors' Addresses Authors' Addresses
Randall R. Stewart Randall R. Stewart
Huawei Adara Networks
Chapin, SC 29036 Chapin, SC 29036
USA USA
Email: randall@lakerest.net Email: randall@lakerest.net
Peter Lei Peter Lei
Cisco Systems, Inc. Cisco Systems, Inc.
8735 West Higgins Road 8735 West Higgins Road
Suite 300 Suite 300
Chicago, IL 60631 Chicago, IL 60631
USA USA
Email: peterlei@cisco.com Email: peterlei@cisco.com
Michael Tuexen Michael Tuexen
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