Network Working Group M. Tuexen Internet-Draft Muenster Univ. of Applied Sciences Expires: December 2, 2006 R. Stewart P. Lei Cisco Systems, Inc. May 31, 2006 Padding Chunk and Parameter for SCTP draft-tuexen-tsvwg-sctp-padding-01.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on December 2, 2006. Copyright Notice Copyright (C) The Internet Society (2006). Abstract This document defines a padding chunk and a padding parameter and describes the required receiver side procedures. Tuexen, et al. Expires December 2, 2006 [Page 1] Internet-Draft Padding Chunk and Parameter for SCTP May 2006 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Padding Chunk (PAD) . . . . . . . . . . . . . . . . . . . . . . 3 3. Padding Parameter (PAD) . . . . . . . . . . . . . . . . . . . . 3 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 6. Normative References . . . . . . . . . . . . . . . . . . . . . 4 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 Intellectual Property and Copyright Statements . . . . . . . . . . 7 Tuexen, et al. Expires December 2, 2006 [Page 2] Internet-Draft Padding Chunk and Parameter for SCTP May 2006 1. Introduction This document defines a padding chunk and a padding parameter and describes the required receiver side procedures. The PAD chunk can be used for path MTU discovery. 2. Padding Chunk (PAD) This chunk is used to pad an SCTP packet to an arbitrary size. 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) Set to zero on transmit and ignored on receipt. Length: 2 bytes (unsigned integer) This value holds the length of the Padding Data plus 4. Padding Data: n bytes (unsigned integer) This holds the Padding Data. The Padding Data is 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 the PAD chunk when it is unknown by the receiver. 3. Padding Parameter (PAD) This parameter is used to pad an INIT chunk to an arbitrary size. Tuexen, et al. Expires December 2, 2006 [Page 3] Internet-Draft Padding Chunk and Parameter for SCTP May 2006 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 4. IANA Considerations A chunk type for the PAD chunk has to be assigned by IANA. It is suggested to use the value given above. It is required that the high order bits of the chunk type are 10. A parameter type for the PAD parameter has to be assigned by IANA. It is suggested to use the value given above. It is required that the high order bits of the parameter type are 10. 5. Security Considerations This document does not require any security considerations in addition to the one given in RFC2960 [1]. 6. Normative References [1] Stewart, R., Xie, Q., Morneault, K., Sharp, C., Schwarzbauer, H., Taylor, T., Rytina, I., Kalla, M., Zhang, L., and V. Paxson, Tuexen, et al. Expires December 2, 2006 [Page 4] Internet-Draft Padding Chunk and Parameter for SCTP May 2006 "Stream Control Transmission Protocol", RFC 2960, October 2000. Tuexen, et al. Expires December 2, 2006 [Page 5] Internet-Draft Padding Chunk and Parameter for SCTP May 2006 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: +1 847 870 7201 Email: peterlei@cisco.com Tuexen, et al. Expires December 2, 2006 [Page 6] Internet-Draft Padding Chunk and Parameter for SCTP May 2006 Intellectual Property Statement 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. 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Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Tuexen, et al. Expires December 2, 2006 [Page 7]