IP Header Compression over PPP
RFC 3544
Document | Type |
RFC - Proposed Standard
(July 2003; No errata)
Obsoletes RFC 2509
Was draft-koren-pppext-rfc2509bis (individual in int area)
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Authors | Stephen Casner , Thima Koren , Carsten Bormann | ||
Last updated | 2013-03-02 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 3544 (Proposed Standard) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Allison Mankin | ||
IESG note | IPHC over PPP is quite useful for tunnels and for 3GPP2 folks - this bis adds support for ECRTP (see draft-ietf-avt-ecrtp) and some fixes that were waiting for a rev for quite a while. Also reviewed by Thomas Narten. | ||
Send notices to | <engan@sm.luth.se> |
Network Working Group T. Koren Request for Comments: 3544 Cisco Systems Obsoletes: 2509 S. Casner Category: Standards Track Packet Design C. Bormann Universitaet Bremen TZI July 2003 IP Header Compression over PPP 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 Internet Society (2003). All Rights Reserved. Abstract This document describes an option for negotiating the use of header compression on IP datagrams transmitted over the Point-to-Point Protocol (RFC 1661). It defines extensions to the PPP Control Protocols for IPv4 and IPv6 (RFC 1332, RFC 2472). Header compression may be applied to IPv4 and IPv6 datagrams in combination with TCP, UDP and RTP transport protocols as specified in RFC 2507, RFC 2508 and RFC 3545. 1. Introduction The IP Header Compression (IPHC) defined in [RFC2507] may be used for compression of both IPv4 and IPv6 datagrams or packets encapsulated with multiple IP headers. IPHC is also capable of compressing both TCP and UDP transport protocol headers. The IP/UDP/RTP header compression defined in [RFC2508] and [RFC3545] fits within the framework defined by IPHC so that it may also be applied to both IPv4 and IPv6 packets. Koren, et al. Standards Track [Page 1] RFC 3544 IP Header Compression over PPP July 2003 In order to establish compression of IP datagrams sent over a PPP link each end of the link must agree on a set of configuration parameters for the compression. The process of negotiating link parameters for network layer protocols is handled in PPP by a family of network control protocols (NCPs). Since there are separate NCPs for IPv4 and IPv6, this document defines configuration options to be used in both NCPs to negotiate parameters for the compression scheme. This document obsoletes RFC 2509, adding two new suboptions to the IP header compression configuration option. One suboption negotiates usage of Enhanced RTP-Compression (specified in [RFC3545]), and the other suboption negotiates header compression for only TCP or only non-TCP packets. IPHC relies on the link layer's ability to indicate the types of datagrams carried in the link layer frames. In this document nine new types for the PPP Data Link Layer Protocol Field are defined along with their meaning. In general, header compression schemes that use delta encoding of compressed packets require that the lower layer does not reorder packets between compressor and decompressor. IPHC uses delta encoding of compressed packets for TCP and RTP. The IPHC specification [RFC2507] includes methods that allow link layers that may reorder packets to be used with IPHC. Since PPP does not reorder packets these mechanisms are disabled by default. When using reordering mechanisms such as multiclass multilink PPP [RFC2686], care must be taken so that packets that share the same compression context are not reordered. 2. Configuration Option This document specifies a new compression protocol value for the IPCP IP-Compression-Protocol option as specified in [RFC1332]. The new value and the associated option format are described in section 2.1. The option format is structured to allow future extensions to the IPHC scheme. NOTE: The specification of link and network layer parameter negotiation for PPP [RFC1661], [RFC1331], [RFC1332] does not prohibit multiple instances of one configuration option but states that the specification of a configuration option must explicitly allow multiple instances. [RFC3241] updates RFC 1332 by explicitly allowing the sending of multiple instances of the IP- Compression-Protocol configuration option, each with a different value for IP-Compression-Protocol. Each type of compression protocol may independently establish its own parameters. Koren, et al. Standards Track [Page 2] RFC 3544 IP Header Compression over PPP July 2003 NOTE: [RFC1332] is not explicit about whether the option negotiates the capabilities of the receiver or of the sender. In keeping with current practice, we assume that the option describesShow full document text