draft-ietf-tsvwg-sctp-padding-02.txt   rfc4820.txt 
Network Working Group M. Tuexen Network Working Group M. Tuexen
Internet-Draft Muenster Univ. of Applied Sciences Request for Comments: 4820 Muenster Univ. of Applied Sciences
Intended status: Standards Track R. Stewart Category: Standards Track R. Stewart
Expires: April 19, 2007 P. Lei P. Lei
Cisco Systems, Inc. Cisco Systems, Inc.
October 16, 2006
Padding Chunk and Parameter for SCTP
draft-ietf-tsvwg-sctp-padding-02.txt
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The list of current Internet-Drafts can be accessed at Padding Chunk and Parameter
http://www.ietf.org/ietf/1id-abstracts.txt. for the Stream Control Transmission Protocol (SCTP)
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and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2006). Copyright (C) The IETF Trust (2007).
Abstract Abstract
This document defines a padding chunk and a padding parameter and This document defines a padding chunk and a padding parameter and
describes the required receiver side procedures. The padding chunk describes the required receiver side procedures. The padding chunk
is used to pad an SCTP packet to an arbitrary size. The padding is used to pad a Stream Control Transmission Protocol (SCTP) packet
parameter is used to pad an SCTP INIT chunk to an arbitrary size. to an arbitrary size. The padding parameter is used to pad an SCTP
INIT chunk to an arbitrary size.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Padding Chunk (PAD) . . . . . . . . . . . . . . . . . . . . . . 3 3. Padding Chunk (PAD) . . . . . . . . . . . . . . . . . . . . . . 2
4. Padding Parameter (PAD) . . . . . . . . . . . . . . . . . . . . 4 4. Padding Parameter (PAD) . . . . . . . . . . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
5.1. A New Chunk Type . . . . . . . . . . . . . . . . . . . . . 5 5.1. A New Chunk Type . . . . . . . . . . . . . . . . . . . . . 4
5.2. A New Parameter Type . . . . . . . . . . . . . . . . . . . 5 5.2. A New Parameter Type . . . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 4
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 5 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 4
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.1. Normative References . . . . . . . . . . . . . . . . . . . 6 8.1. Normative References . . . . . . . . . . . . . . . . . . . 5
8.2. Informative References . . . . . . . . . . . . . . . . . . 6 8.2. Informative References . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6
Intellectual Property and Copyright Statements . . . . . . . . . . 8
1. Introduction 1. Introduction
This document defines a padding chunk and a padding parameter and This document defines a padding chunk and a padding parameter and
describes the required receiver side procedures. The padding chunk describes the required receiver side procedures. The padding chunk
is used to pad an SCTP packet to an arbitrary size. The padding is used to pad an SCTP packet to an arbitrary size. The padding
parameter is used to pad an SCTP INIT chunk to an arbitrary size. parameter is used to pad an SCTP INIT chunk to an arbitrary size.
The usage of the PAD chunk for path MTU discovery is described in The usage of the PAD chunk for path MTU discovery is described in
PMTU [3]. The inappropriate usage of the PAD parameter or PAD chunk PMTU [4]. The inappropriate usage of the PAD parameter or PAD chunk
can result in wasted bandwidth. can result in wasted bandwidth.
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", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL", when they appear in this document, are to be interpreted "OPTIONAL", when they appear in this document, are to be interpreted
as described in RFC2119 [1]. as described in RFC2119 [1].
3. Padding Chunk (PAD) 3. Padding Chunk (PAD)
skipping to change at page 3, line 41 skipping to change at page 2, line 41
| Type = 0x84 | Flags=0 | Length | | Type = 0x84 | Flags=0 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
\ Padding Data / \ Padding Data /
/ \ / \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1 Figure 1
Type: 1 byte (unsigned integer) Type: 1 byte (unsigned integer)
This value MUST be set to 0x84 for all PAD-chunks. This value MUST be set to 0x84 for all PAD chunks.
Flags: 1 byte (unsigned integer) Flags: 1 byte (unsigned integer)
This value SHOULD be set to zero on transmit and MUST be ignored This value SHOULD be set to zero on transmit and MUST be ignored
on receipt. on receipt.
Length: 2 bytes (unsigned integer) Length: 2 bytes (unsigned integer)
This value holds the length of the Padding Data plus 4. This value holds the length of the Padding Data plus 4.
Padding Data: n bytes (unsigned integer) Padding Data: n bytes (unsigned integer)
This holds the Padding Data. The Padding Data MUST be ignored by This holds the Padding Data. The Padding Data MUST be ignored by
the receiver. the receiver.
The receiver of the PAD chunk MUST discard this chunk and continue The receiver of the PAD chunk MUST discard this chunk and continue
processing the rest of the chunks in the packet. Please note that processing the rest of the chunks in the packet. Please note that
this is also the required processing behavior for any unknown chunk this is also the required processing behavior for any unknown chunk
having the same highest order two bits of the type as the PAD chunk. having the same highest-order two bits of the type as the PAD chunk.
4. Padding Parameter (PAD) 4. Padding Parameter (PAD)
This parameter is used to pad an INIT chunk. A PAD parameter can be This parameter is used to pad an INIT chunk. A PAD parameter can be
used to enlarge the INIT chunk by 4 bytes as the minimum to the used to enlarge the INIT chunk by 4 bytes as the minimum to the
maximum size of the INIT chunk in steps of 4 bytes. An INIT chunk maximum size of the INIT chunk in steps of 4 bytes. An INIT chunk
MAY contain multiple PAD parameters. MAY contain multiple PAD parameters.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
skipping to change at page 4, line 50 skipping to change at page 4, line 7
NOT be included in any other chunk. The receiver of the PAD NOT be included in any other chunk. The receiver of the PAD
parameter MUST silently discard this parameter and continue parameter MUST silently discard this parameter and continue
processing the rest of the INIT chunk. This means that the size of processing the rest of the INIT chunk. This means that the size of
the generated COOKIE parameter in the INIT-ACK MUST NOT depend on the the generated COOKIE parameter in the INIT-ACK MUST NOT depend on the
existence of the PAD parameter in the INIT chunk. A receiver of a existence of the PAD parameter in the INIT chunk. A receiver of a
PAD parameter MUST NOT include the PAD parameter within any State PAD parameter MUST NOT include the PAD parameter within any State
Cookie parameter it generates. Cookie parameter it generates.
5. IANA Considerations 5. IANA Considerations
[NOTE to RFC-Editor: This document is the reference for all registrations described in
this section. All registrations have been listed in the document
"RFCXXXX" is to be replaced by the RFC number you assign this available at sctp-parameters [3]. The changes are described below.
document.
]
This document (RFCXXX) is the reference for all registrations
described in this section. All registrations need to be listed in
the document available at sctp-parameters [4]. The suggested changes
are described below.
5.1. A New Chunk Type 5.1. A New Chunk Type
A chunk type for the PAD chunk has to be assigned by IANA. It is A chunk type for the PAD chunk has been assigned by IANA. The value
suggested to use the value given in Figure 1. This requires an has been assigned as described in Figure 1. The following has been
additional line in the "CHUNK TYPES" table of sctp-parameters [4]: added to the "CHUNK TYPES" table of sctp-parameters [3]:
CHUNK TYPES CHUNK TYPES
ID Value Chunk Type Reference ID Value Chunk Type Reference
-------- ---------- --------- -------- ---------- ---------
132(0x84) Padding Chunk (PAD) [RFCXXXX] 132(0x84) Padding Chunk (PAD) [RFC4820]
5.2. A New Parameter Type 5.2. A New Parameter Type
A parameter type has to be assigned for the PAD parameter by IANA. A parameter type has been assigned for the PAD parameter by IANA.
It is suggested to use the values given in Figure 2. This requires a The value has been assigned as described in Figure 2. The following
modification in the "CHUNK PARAMETER TYPES" table in sctp- has been added to the "CHUNK PARAMETER TYPES" table in sctp-
parameters [4]: Add a new line to the "INIT Chunk Parameter Types" parameters [3]:
table:
INIT Chunk Parameter Types
Chunk Parameter Type Value Chunk Parameter Type Value
-------------------- ----- -------------------- -----
Padding 32773(0x8005) Padding 32773(0x8005)
6. Security Considerations 6. Security Considerations
This document does not add any additional security considerations in This document does not add any additional security considerations to
addition to the ones given in RFC2960 [2]. the ones given in RFC 2960 [2].
7. Acknowledgments 7. Acknowledgments
The authors wish to thank Matthew J. Zekauskas, and Lars Eggert for The authors wish to thank Matthew J. Zekauskas and Lars Eggert for
his invaluable comments. their invaluable comments.
8. References 8. References
8.1. Normative References 8.1. Normative References
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997. Levels", BCP 14, RFC 2119, March 1997.
[2] Stewart, R., Xie, Q., Morneault, K., Sharp, C., Schwarzbauer, [2] Stewart, R., Xie, Q., Morneault, K., Sharp, C., Schwarzbauer,
H., Taylor, T., Rytina, I., Kalla, M., Zhang, L., and V. Paxson, H., Taylor, T., Rytina, I., Kalla, M., Zhang, L., and V. Paxson,
"Stream Control Transmission Protocol", RFC 2960, October 2000. "Stream Control Transmission Protocol", RFC 2960, October 2000.
8.2. Informative References 8.2. Informative References
[3] Mathis, M. and J. Heffner, "Packetization Layer Path MTU [3] "IANA registry",
Discovery", draft-ietf-pmtud-method-10 (work in progress), <http://www.iana.org/assignments/sctp-parameters>.
September 2006.
URIs
[4] <http://www.iana.org/assignments/sctp-parameters> [4] Mathis, M. and J. Heffner, "Packetization Layer Path MTU
Discovery", RFC 4821, March 2007.
Authors' Addresses Authors' Addresses
Michael Tuexen Michael Tuexen
Muenster Univ. of Applied Sciences Muenster Univ. of Applied Sciences
Stegerwaldstr. 39 Stegerwaldstr. 39
48565 Steinfurt 48565 Steinfurt
Germany Germany
Email: tuexen@fh-muenster.de EMail: tuexen@fh-muenster.de
Randall R. Stewart Randall R. Stewart
Cisco Systems, Inc. Cisco Systems, Inc.
4875 Forest Drive 4875 Forest Drive
Suite 200 Suite 200
Columbia, SC 29206 Columbia, SC 29206
USA USA
Email: rrs@cisco.com EMail: rrs@cisco.com
Peter Lei Peter Lei
Cisco Systems, Inc. Cisco Systems, Inc.
955 Happfield Dr. 955 Happfield Dr.
Arlington Heights, IL 60004 Arlington Heights, IL 60004
US US
Phone: +1 773 695-8201 Phone: +1 773 695-8201
Email: peterlei@cisco.com EMail: peterlei@cisco.com
Full Copyright Statement Full Copyright Statement
Copyright (C) The Internet Society (2006). Copyright (C) The IETF Trust (2007).
This document is subject to the rights, licenses and restrictions This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors contained in BCP 78, and except as set forth therein, the authors
retain all their rights. retain all their rights.
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property Intellectual Property
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information made any independent effort to identify any such rights. Information
skipping to change at page 8, line 45 skipping to change at page 6, line 45
such proprietary rights by implementers or users of this such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at specification can be obtained from the IETF on-line IPR repository at
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Acknowledgment Acknowledgement
Funding for the RFC Editor function is provided by the IETF Funding for the RFC Editor function is currently provided by the
Administrative Support Activity (IASA). Internet Society.
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