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diff --git a/doc/rfc/rfc4820.txt b/doc/rfc/rfc4820.txt new file mode 100644 index 0000000..4b9b241 --- /dev/null +++ b/doc/rfc/rfc4820.txt @@ -0,0 +1,339 @@ + + + + + + +Network Working Group M. Tuexen +Request for Comments: 4820 Muenster Univ. of Applied Sciences +Category: Standards Track R. Stewart + P. Lei + Cisco Systems, Inc. + March 2007 + + + Padding Chunk and Parameter + for the Stream Control Transmission Protocol (SCTP) + +Status of This Memo + + This document specifies an Internet standards track protocol for the + Internet community, and requests discussion and suggestions for + improvements. Please refer to the current edition of the "Internet + Official Protocol Standards" (STD 1) for the standardization state + and status of this protocol. Distribution of this memo is unlimited. + +Copyright Notice + + Copyright (C) The IETF Trust (2007). + +Abstract + + This document defines a padding chunk and a padding parameter and + describes the required receiver side procedures. The padding chunk + is used to pad a Stream Control Transmission Protocol (SCTP) packet + to an arbitrary size. The padding parameter is used to pad an SCTP + INIT chunk to an arbitrary size. + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 + 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . 2 + 3. Padding Chunk (PAD) . . . . . . . . . . . . . . . . . . . . . . 2 + 4. Padding Parameter (PAD) . . . . . . . . . . . . . . . . . . . . 3 + 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 + 5.1. A New Chunk Type . . . . . . . . . . . . . . . . . . . . . 4 + 5.2. A New Parameter Type . . . . . . . . . . . . . . . . . . . 4 + 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 + 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 4 + 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 + 8.1. Normative References . . . . . . . . . . . . . . . . . . . 5 + 8.2. Informative References . . . . . . . . . . . . . . . . . . 5 + + + + + + +Tuexen, et al. Standards Track [Page 1] + +RFC 4820 Padding Chunk and Parameter for SCTP March 2007 + + +1. Introduction + + This document defines a padding chunk and a padding parameter and + describes the required receiver side procedures. The padding chunk + 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. + The usage of the PAD chunk for path MTU discovery is described in + PMTU [4]. The inappropriate usage of the PAD parameter or PAD chunk + can result in wasted bandwidth. + +2. Conventions + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and + "OPTIONAL", when they appear in this document, are to be interpreted + as described in RFC 2119 [1]. + +3. Padding Chunk (PAD) + + This chunk is used to pad an SCTP packet. A PAD chunk can be used to + enlarge the packet by 4 to 65536 bytes in steps of 4 bytes. An SCTP + packet MAY contain multiple PAD chunks. + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Type = 0x84 | Flags=0 | Length | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + \ Padding Data / + / \ + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Figure 1 + + Type: 1 byte (unsigned integer) + This value MUST be set to 0x84 for all PAD chunks. + + Flags: 1 byte (unsigned integer) + This value SHOULD be set to zero on transmit and MUST be ignored + on receipt. + + Length: 2 bytes (unsigned integer) + This value holds the length of the Padding Data plus 4. + + + + + + + +Tuexen, et al. Standards Track [Page 2] + +RFC 4820 Padding Chunk and Parameter for SCTP March 2007 + + + Padding Data: n bytes (unsigned integer) + This holds the Padding Data. The Padding Data MUST be ignored by + the receiver. + + The receiver of the PAD chunk MUST discard this chunk and continue + processing the rest of the chunks in the packet. Please note that + 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. + +4. Padding Parameter (PAD) + + 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 + maximum size of the INIT chunk in steps of 4 bytes. An INIT chunk + MAY contain multiple PAD parameters. + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Parameter Type = 0x8005 | Parameter Length | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + / / + \ Padding Data \ + / / + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Figure 2 + + Parameter Type: 2 bytes (unsigned integer) + This value MUST be set to 0x8005. + + Parameter Length: 2 bytes (unsigned integer) + This value holds the length of the Padding Data plus 4. + + The PAD parameter MAY be included only in the INIT chunk. It MUST + NOT be included in any other chunk. The receiver of the PAD + parameter MUST silently discard this parameter and continue + 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 + existence of the PAD parameter in the INIT chunk. A receiver of a + PAD parameter MUST NOT include the PAD parameter within any State + Cookie parameter it generates. + + + + + + + + + +Tuexen, et al. Standards Track [Page 3] + +RFC 4820 Padding Chunk and Parameter for SCTP March 2007 + + +5. IANA Considerations + + This document is the reference for all registrations described in + this section. All registrations have been listed in the document + available at sctp-parameters [3]. The changes are described below. + +5.1. A New Chunk Type + + A chunk type for the PAD chunk has been assigned by IANA. The value + has been assigned as described in Figure 1. The following has been + added to the "CHUNK TYPES" table of sctp-parameters [3]: + + CHUNK TYPES + + ID Value Chunk Type Reference + -------- ---------- --------- + 132(0x84) Padding Chunk (PAD) [RFC4820] + +5.2. A New Parameter Type + + A parameter type has been assigned for the PAD parameter by IANA. + The value has been assigned as described in Figure 2. The following + has been added to the "CHUNK PARAMETER TYPES" table in sctp- + parameters [3]: + + INIT Chunk Parameter Types + + Chunk Parameter Type Value + -------------------- ----- + Padding 32773(0x8005) + +6. Security Considerations + + This document does not add any additional security considerations to + the ones given in RFC 2960 [2]. + +7. Acknowledgments + + The authors wish to thank Matthew J. Zekauskas and Lars Eggert for + their invaluable comments. + + + + + + + + + + + +Tuexen, et al. Standards Track [Page 4] + +RFC 4820 Padding Chunk and Parameter for SCTP March 2007 + + +8. References + +8.1. Normative References + + [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement + Levels", BCP 14, RFC 2119, March 1997. + + [2] Stewart, R., Xie, Q., Morneault, K., Sharp, C., Schwarzbauer, + H., Taylor, T., Rytina, I., Kalla, M., Zhang, L., and V. Paxson, + "Stream Control Transmission Protocol", RFC 2960, October 2000. + +8.2. Informative References + + [3] "IANA registry", + <http://www.iana.org/assignments/sctp-parameters>. + + [4] Mathis, M. and J. Heffner, "Packetization Layer Path MTU + Discovery", RFC 4821, March 2007. + +Authors' Addresses + + Michael Tuexen + Muenster Univ. of Applied Sciences + Stegerwaldstr. 39 + 48565 Steinfurt + Germany + + EMail: tuexen@fh-muenster.de + + + Randall R. Stewart + Cisco Systems, Inc. + 4875 Forest Drive + Suite 200 + Columbia, SC 29206 + USA + + EMail: rrs@cisco.com + + + Peter Lei + Cisco Systems, Inc. + 955 Happfield Dr. + Arlington Heights, IL 60004 + US + + Phone: +1 773 695-8201 + EMail: peterlei@cisco.com + + + +Tuexen, et al. Standards Track [Page 5] + +RFC 4820 Padding Chunk and Parameter for SCTP March 2007 + + +Full Copyright Statement + + Copyright (C) The IETF Trust (2007). + + This document is subject to the rights, licenses and restrictions + contained in BCP 78, and except as set forth therein, the authors + retain all their rights. + + This document and the information contained herein are provided on an + "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS + OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND + THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS + OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF + THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED + WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Intellectual Property + + The IETF takes no position regarding the validity or scope of any + Intellectual Property Rights or other rights that might be claimed to + pertain to the implementation or use of the technology described in + 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 + made any independent effort to identify any such rights. Information + on the procedures with respect to rights in RFC documents can be + found in BCP 78 and BCP 79. + + Copies of IPR disclosures made to the IETF Secretariat and any + assurances of licenses to be made available, or the result of an + attempt made to obtain a general license or permission for the use of + such proprietary rights by implementers or users of this + specification can be obtained from the IETF on-line IPR repository at + http://www.ietf.org/ipr. + + The IETF invites any interested party to bring to its attention any + copyrights, patents or patent applications, or other proprietary + rights that may cover technology that may be required to implement + this standard. Please address the information to the IETF at + ietf-ipr@ietf.org. + +Acknowledgement + + Funding for the RFC Editor function is currently provided by the + Internet Society. + + + + + + + +Tuexen, et al. Standards Track [Page 6] + |