IPDVB Working Group G. Fairhurst Internet-Draft University of Aberdeen Updates: 4326 (if approved) May 10, 2013 Intended status: Standards Track Expires: November 11, 2013 IANA Guidance for Managing the ULE Registry draft-fairhurst-ipdvb-ule-iana-01 Abstract This document proposes an update to RFC 4326 to clarify and update the allocation rules for the Unidirectional Lightweight Encapsulation (ULE) next header registry. This registry is used by ULE and Generic Stream Encapsulation (GSE) to record the codepoints of extension headers and protocols supported by these encapsulation protocols. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on November 11, 2013. Copyright Notice Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved. Fairhurst Expires November 11, 2013 [Page 1]
Internet-Draft IANA ULE guidelines May 2013 This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. The ULE Next Header Registries . . . . . . . . . . . . . 3 3. Updated IANA guidance on allocation in the ULE Next Header Registry . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3.1. ULE Next-Header Registry . . . . . . . . . . . . . . . . 3 3.2. IANA Guidelines . . . . . . . . . . . . . . . . . . . . . 3 3.3. Reservation of Next Header values . . . . . . . . . . . . 4 4. Update to registry information . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 5 8. Revision Notes . . . . . . . . . . . . . . . . . . . . . . . 5 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 9.1. Normative References . . . . . . . . . . . . . . . . . . 5 9.2. Informative References . . . . . . . . . . . . . . . . . 6 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction The Unidirectional Lightweight Encapsulation (ULE) [RFC4326] specifies an encapsulation for links that employ the MPEG-2 Transport Stream, with support over a wide variety of physical-layer bearers [RFC4259]. The encapsulation header includes a Type field that identifies payload types and extension headers (e.g.[RFC5163]). The ULE specification requested IANA to maintain the ULE next header registries to record the allocation of the values used to construct this Type field. The Digital Video Broadcast (DVB) Project has published an encapsulation for second-generation DVB physical layers. This specifies the Generic Stream Encapsulation [GSE]. This encapsulation shares many of the network properties of ULE and uses a common format for the Type field [RFC5163]. The ULE Next Header registries are therefore also applicable to this encapsulation. Fairhurst Expires November 11, 2013 [Page 2]
Internet-Draft IANA ULE guidelines May 2013 2. Terminology This document assumes familiarity with the terminology of ULE [RFC4326] and [RFC5163]. 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 [RFC2119]. 2.1. The ULE Next Header Registries The Mandatory Extension Headers registry allocates values in the range 0-255. These values are used to identify mandatory extension headers. The registered value corresponds to the 16-bit Type value for the mandatory extension header or the specified protocol. The Optional Extension Headers registry allocates values in the range 256-512. These values are used to identify optional extension headers. The registered value corresponds to the 16-bit Type value that would be used for an optional extension header with a length (H-LEN) of 1. 3. Updated IANA guidance on allocation in the ULE Next Header Registry The rules for allocation are defined in section 11 of [RFC4326]. This document updates these rules by replacing these, replacing these with the rules in this section: Allocations in the ULE Next Header Registry are to be assigned by IANA using the "Expert Review" policy defined in [RFC5226]. Applications for registration are expected to include a reference to a published specification of the next header extension in a standards document. An IETF standards-track RFC can provide such a reference. Other specifications are also permitted. The expert shall advise IANA on whether a particular specification constitutes a standards document. 3.1. ULE Next-Header Registry This registry allocates Next-Header values within the range 0-511 (decimal). For each allocated value, it also specifies the set of allowed H-LEN values (see [RFC4326] section 5). In combination, these define a set of allowed values in the range 0-1535 for the first part of the ULE Type space (see [RFC4326] section 4.4.1). 3.2. IANA Guidelines Fairhurst Expires November 11, 2013 [Page 3]
Internet-Draft IANA ULE guidelines May 2013 The following contains the IANA guidelines for management of the ULE Next-Header registry. This registry allocates values 0-511 decimal (0x0000-0x01FF, hexadecimal). It MUST NOT allocate values greater than 0x01FF (decimal). It The Next-Header registry is divided into two areas: 1. 0-255 (decimal) IANA-assigned values, indicating Mandatory Extension Headers (or link-dependent Type fields). Requests for assignment in this area MUST define the value and the name associated with the Extension Header, together with the procedure for processing the Extension Header. This MUST also define the need for the Mandatory Extension and the intended use. [RFC4326] made initial assignments to this registry updated by later requests. 2. 256-511 (decimal) IANA-assigned values, indicating Optional Extension Headers. Requests for assignment in this area MUST define the value and the name associated with the Extension Header, together with the procedure for processing the Extension Header. The entry MUST specify the range of allowable H-LEN values that are permitted (in the range 1-5). It MUST also define the need for the Optional Extension and the intended use. [RFC4326] made initial assignments to this registry updated by later requests. 3.3. Reservation of Next Header values This document reserves the range decimal 144-159 (0x80-0x8F). These reserved values are presently not available for general assignment, and will not be allocated until the registry is exhausted. 4. Update to registry information This section requests IANA to record additional explanatory note in the registry: "The Mandatory Extension Headers registry allocates values in the range 0-255. These values are used to identify mandatory extension headers. The registered value corresponds to the 16-bit Type value for the mandatory extension header or the specified protocol. The Optional Extension Headers registry allocates values in the range 256-512. These values are used to identify optional extension headers. The registered value corresponds to the 16-bit Type value that would be used for an optional extension header with a length (H-LEN) of 1." Fairhurst Expires November 11, 2013 [Page 4]
Internet-Draft IANA ULE guidelines May 2013 5. Security Considerations This document does not present new security considerations. 6. IANA Considerations Section 3 specifies updated IANA allocation rules Section 4 requests IANA to update the registry information. 7. Acknowledgments The author acknowledges feedback from IANA, Alexander Adolf and Hans- Peter Lexow on usage of this registry. 8. Revision Notes RFC-Editor: Please remove this section prior to publication Draft 00 This was the first revision - it proposed the requested update. Draft 01 This revision is thought complete and replaces the entire IANA section with the new text. 9. References 9.1. Normative References [GSE] European Telecommunication Standards, Institute (ETSI), "Digital Video Broadcasting (DVB); Generic Stream Encapsulation (GSE) Protocol", 2007. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4326] Fairhurst, G. and B. Collini-Nocker, "Unidirectional Lightweight Encapsulation (ULE) for Transmission of IP Datagrams over an MPEG-2 Transport Stream (TS)", RFC 4326, December 2005. [RFC5163] Fairhurst, G. and B. Collini-Nocker, "Extension Formats for Unidirectional Lightweight Encapsulation (ULE) and the Generic Stream Encapsulation (GSE)", RFC 5163, April 2008. Fairhurst Expires November 11, 2013 [Page 5]
Internet-Draft IANA ULE guidelines May 2013 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. 9.2. Informative References [RFC4259] Montpetit, M.-J., Fairhurst, G., Clausen, H., Collini- Nocker, B., and H. Linder, "A Framework for Transmission of IP Datagrams over MPEG-2 Networks", RFC 4259, November 2005. Author's Address Godred Fairhurst University of Aberdeen School of Engineering Fraser Noble Building Aberdeen, Scotland AB24 3UE UK Email: gorry@erg.abdn.ac.uk URI: http://www.erg.abdn.ac.uk Fairhurst Expires November 11, 2013 [Page 6]