Network Working Group Eric Gray Internet Draft John Rutemiller Category: Standards Track Marconi Communications, Inc. Expiration Date: January 2006 George Swallow Cisco Systems, Inc. July 2005 Internet Code Point Assignments draft-gray-rfc1888bis-01 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. This document may not be modified, and derivative works of it may not be created, except to publish it as an RFC, reformat it for readability or translate it into languages other than English. 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/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at: http://www.ietf.org/shadow.html Abstract This document is intended to accomplish two highly inter-related tasks: to establish an "initial" Internet Code Point (ICP) assignment for each of IPv4 and IPv6 address encoding in Network Service Access Point (NSAP) Addresses, and to recommend an IANA assignment policy for currently unassigned ICP values. In the first task, this document is a partial replacement for RFC 1888 - particularly for section 6 of RFC 1888. In the second task, this document incorporates wording and specifications from ITU recommendation X.213 and further recommends that IANA use the "IETF consensus" assignment policy in making future ICP assignments. Internet Draft Expires January 2006 Page 1 Gray, et al Internet Code Point Assignments February 2005 TABLE OF CONTENTS 1. Introduction .................................................. 2 1.1. Conventions ................................................. 3 1.2. Acronyms and Terminology .................................... 3 2. IANA Considerations ........................................... 3 3. Initial Allocations and Uses .................................. 4 3.1. IPv4 Address Encoding in an NSAPA ........................... 4 3.2. IPv6 Address Encoding in an NSAPA ........................... 5 4. Security Considerations ....................................... 6 5. References .................................................... 6 5.1 Normative References ......................................... 6 5.2 Informative References ....................................... 6 6. Author Information ............................................ 7 7. Copyright Notice .............................................. 7 8. Intellectual Property Notice .................................. 8 9. Acknowledgement ............................................... 8 1. Introduction Section 6 of RFC 1888 [1888] previously provided for assignment of the initial Internet Code Point (ICP) value '0' for encoding an IPv6 address in a Network Service Access (or Attachment) Point (NSAP) address. RFC 1888 also defined multiple means for restricted encoding of an NSAP address in an IPv6 address. The means RFC 1888 defined for encoding NSAP addresses in IPv6 address format, was heavily annotated with warnings and limitations that apply should this encoding be used. Possibly as a result, these encodings are not used and appear never to have been used in any IPv6 deployment. In addition, section 6 contains minor errors. As a result of these various considerations, an Internet Draft [BC] has been submitted recommending that RFC 1888 be made historical. It is the belief of the authors of this document that the errors in section 6 of RFC 1888 were - at least in part - the result of the fact that the ITU specification [X.213] that originally assigned Authority and Format Indentifier (AFI) 35 to IANA was not freely publicized, nor was it incorporated or explained using the mechanism commonly used in the IETF - i.e. - via an RFC. It is therefore part of the purpose of this document to provide that explanation. In addition, because there are other documents that refer to the IPv6 ICP assignment in RFC 1888, it is necessary for the errors in section 6 of RFC 1888 to be corrected - irrespective of the RFC's ultimate status. Finally, no previous RFC - including RFC 1888 - has ever formalized Internet Draft Expires January 2006 Page 2 Gray, et al Internet Code Point Assignments February 2005 an assignment of an IPv4 ICP. This may have been - in part - because of a lack of formal definition of an IANA assignment policy for ICP values under the IANA allocated AFI (35). This document replaces section 6 of RFC 1888 in defining the ICP for IPv6 address encoding in an NSAP address - and - formalizes the ICP assignment for IPv4 address encoding in an NSAP address. 1.1. Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [2119]. 1.2. Acronyms and Terminology AFI - Authority and Format Identifier BCD - Binary Coded Decimal DSP - Domain Specific Part IANA - Internet Assigned Number Authority ICP - Internet Code Point IDI - Initial Domain Identifier IDP - Initial Domain Part IETF - Internet Engineering Task Force ISO - International Standardization Organization NSAP - Network Service Access (or Attachment) Point (often NSAPA) NSAPA - NSAP Address; 20 Octet Address Format OSI - Open Systems Interconnect RFC - Request For Comments WIP - Work In Progress 2. IANA Considerations An ITU Recommendation [X.213] has allocated two AFI designating IANA as the assignment authority. One of these two AFI ('34') is allocated for assignment of NSAPA in Decimal Numeric Format. This document does not address allocation for this AFI as it is not clear what - if any - use can be made of this encoding format at this time. The other AFI ('35') is to be used for binary encoding except as noted below. The NSAPA format consists of an Initial Domain Part (IDP) and Domain Specific Part (DSP). The IDP, in turn, consists of an Authority and Format Identifier (AFI) and an Initial Domain Identifier (IDI). The AFI is defined to be a binary octet and the IDI is defined to be four decimal encoded in two octets using Binary Coded Decimal format. Each nibble of the IDI is used to represent a decimal digit - using binary value '0000' through '1001'. In assigning allocation authority for AFI '35' to IANA, ITU-T Internet Draft Expires January 2006 Page 3 Gray, et al Internet Code Point Assignments February 2005 [X.213] recommendation specifies that the two octet IDI will be used to hold an Internet Code Point (ICP) which - because of the decimal encoding - MUST be in the decimal range from '0' to '9999'. The ITU recommendation assumes the assignment of ICP '0' (zero) for IPv6 address encoding in an Network Service Access Point Address (NSAPA or - often - NSAP). In addition, ITU-T assumed that IANA would assign an ICP for IPv4 address encoding in an NSAPA and X.213 assumes that the ICP value for this purpose would be '1'. In an NSAPA, the DSP is the remaining octets after the IDP. For AFI '35', this is 17 octets having a format as defined by IANA - or as defined by another party and published with IANA consent. IANA - as the Authority responsible for the Authority and Format Identifier (AFI) '35' - SHOULD NOT assign an ICP unless there is a corresponding defined, and published, format at the time of the code point assignment. As of the time this document is published as an RFC - with consent of IANA - the following ICP values are assigned: ICP Value Address Encoding Format Definition ---------- ----------------- ---------------------------- '0' IPv6 , section 3.2 '1' IPv4 , section 3.1 Remaining decimal values '2' through '9999' SHOULD be assigned on an IETF consensus basis, with IANA consent. 3. Initial Allocations and Uses This document continues the ICP assignment and format definition as previously defined in RFC 1888, and formalizes the allocation of ICP value '1' for IPv4 encoding and the format to be used. The sections below describe the specific IPv4 and IPv6 address encoding formats. 3.1. IPv4 Address Encoding in an NSAPA If it is required, for whatever reason, to embed an IPv4 address inside a 20-octet NSAP address, then the following format MUST be used. A specific possible use of this embedding is to express an IP address within the ATM Forum address format. Another possible use would be to allow CLNP packets that encapsulate IPv4 packets to be routed in a CLNP network using the IPv4 address architecture. Several leading bytes of the IPv4 address could be used as a CLNP routing prefix. Internet Draft Expires January 2006 Page 4 Gray, et al Internet Code Point Assignments February 2005 An NSAPA with an AFI value of '35' and an ICP value of '1' (one) encodes a 4 byte IPv4 address in the first 4 octets of the DSP. The last 13 octets of the DSP are unspecified in this document. To maintain compatibility with both NSAP format and IPv4 addressing, these octets MUST be present, but have no intrinsic significance for IPv4. The default values for the unspecified octets is zero. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 0-3 | AFI = 0x35 | ICP = 0001 | IPv4 (byte 0)| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 4-7 | IPv4 (bytes 1-3) | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 8-11 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 12-15| | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 16-19| | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ An NSAPA with the IANA AFI code and ICP set to '1' (one) is converted to an IPv4 address by stripping off the first 3 and the last 13 octets. If the NSAP addressed contents are passed to a higher layer, the last 13 octets SHOULD be presented to the higher layer as well. If an NSAP address using this encoding is used for routing in an IPv4 routing architecture, only the 4 byte IPv4 address MAY be considered. 3.2. IPv6 Address Encoding in an NSAPA If it is required, for whatever reason, to embed an IPv6 address inside a 20-octet NSAP address, then the following format MUST be used. A specific possible use of this embedding is to express an IP address within the ATM Forum address format. Another possible use would be to allow CLNP packets that encapsulate IPv6 packets to be routed in a CLNP network using the IPv6 address architecture. Several leading bytes of the IPv6 address could be used as a CLNP routing prefix. An NSAPA with an AFI value of '35' and an ICP value of '0' (zero) encodes a 16 byte IPv6 address in the first 16 octets of the DSP. The last octet of the DSP is a selector. To maintain compatibility with both NSAP format and IPv6 addressing, this octet MUST be present, but it has no intrinsic significance for IPv6. Its default value is zero, but other values may be used as specified for any specific application. For example, this octet may be used to specify one of 255 possible port numbers. Internet Draft Expires January 2006 Page 5 Gray, et al Internet Code Point Assignments February 2005 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 0-3 | AFI = 0x35 | ICP = 0000 | IPv6 (byte 0)| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 4-7 | IPv6 (bytes 1-4) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 8-11 | IPv6 (bytes 5-8) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 12-15| IPv6 (bytes 9-12) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 16-19| IPv6 (bytes 13-15) | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ An NSAPA with the IANA AFI code and ICP set to '0' (zero) is converted to an IPv6 address by stripping off the first three and the twentieth octets. If the NSAP addressed contents are passed to a higher layer, the last octet SHOULD be presented to the higher layer as well. If an NSAP address using this encoding is used for routing in an IPv6 routing architecture, only the 16 byte IPv6 address MAY be considered. 4. Security Considerations Security issues are not specifically addressed in this document, as the NSAP encoding of IPv4 and IPv6 addresses is compatible with the corresponding security mechanisms of RFC 1825 [1825]. 5. References 5.1 Normative References [BCP78] BCP 78/RFC 3667, "IETF Rights in Contributions", Scott Bradner, February 2004. [BCP79] BCP 79/RFC 3668, "Intellectual Property Rights in IETF Technology, Scott Bradner, February 2004. [1825] RFC 1825, "Security Architecture for the Internet Protocol", Ran Atkinson, August 1995. [2119] RFC 2119 / BCP 14, "Key words for use in RFCs to Indicate Requirement Levels", Scott Bradner, March 1997. [NSAP] International Standardization Organization, "Information technology - Open Systems Interconnection - Network service Definition", ISO/IEC 8348:2002, 2002. Internet Draft Expires January 2006 Page 6 Gray, et al Internet Code Point Assignments February 2005 [X.213] ITU-T Recommendation X.213, X-Series Recommendations, Data Networks and Open Systems Communications, October, 2001. 5.2 Informative References [1888] RFC 1888, "OSI NSAPs and IPv6", J. Bound, et al, August 1996. [BC] Internet Draft, "RFC 1888 is Obsolete" (WIP), Brian Carpenter September 2004. 6. Author Information Eric Gray Marconi Communications, Inc. 900 Chelmsford Street Lowell, MA, 01851 E-Mail: Eric.Gray@Marconi.com John Rutemiller Marconi Communications, Inc. 3000 Marconi Drive Warrendale, PA, 15086-7502 E-Mail: John.Rutemiller@Marconi.com George Swallow Cisco Systems, Inc. 1414 Massachusetts Avenue Boxborough, MA, 01719 E-Mail: swallow@cisco.com 7. Copyright Notice Copyright (C) The Internet Society (2005). 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 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. 8. Intellectual Property Notice Internet Draft Expires January 2006 Page 7 Gray, et al Internet Code Point Assignments February 2005 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. 9. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. Internet Draft Expires January 2006 Page 8