Protocol Extensions for Header Compression over MPLS
RFC 4901
Document | Type | RFC - Proposed Standard (June 2007; No errata) | |
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Authors | Jim Hand , Andy Malis , Gerald Ash | ||
Last updated | 2015-10-14 | ||
Replaces | draft-ash-avt-hc-over-mpls-protocol | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 4901 (Proposed Standard) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Cullen Jennings | ||
Send notices to | pwe3-chairs@ietf.org, townsley@cisco.com |
Network Working Group J. Ash, Ed. Request for Comments: 4901 J. Hand, Ed. Category: Standards Track AT&T A. Malis, Ed. Verizon Communications June 2007 Protocol Extensions for Header Compression over MPLS 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 specification defines how to use Multi-Protocol Label Switching (MPLS) to route Header-Compressed (HC) packets over an MPLS label switched path. HC can significantly reduce packet-header overhead and, in combination with MPLS, can also increases bandwidth efficiency and processing scalability in terms of the maximum number of simultaneous compressed flows that use HC at each router). Here we define how MPLS pseudowires are used to transport the HC context and control messages between the ingress and egress MPLS label switching routers. This is defined for a specific set of existing HC mechanisms that might be used, for example, to support voice over IP. This specification also describes extension mechanisms to allow support for future, as yet to be defined, HC protocols. In this specification, each HC protocol operates independently over a single pseudowire instance, very much as it would over a single point-to- point link. Ash, et al. Standards Track [Page 1] RFC 4901 Header Compression over MPLS Protocol June 2007 Table of Contents 1. Introduction ....................................................3 2. Terminology .....................................................3 3. Header Compression over MPLS Protocol Overview ..................6 4. Protocol Specifications ........................................11 4.1. MPLS Pseudowire Setup and Signaling .......................13 4.2. Header Compression Scheme Setup, Negotiation, and Signaling .................................................14 4.2.1. Configuration Option Format [RFC3544] ..............15 4.2.2. RTP-Compression Suboption [RFC3544] ................17 4.2.3. Enhanced RTP-Compression Suboption [RFC3544] .......18 4.2.4. Negotiating Header Compression for Only TCP or Only Non-TCP Packets [RFC3544] ..................19 4.2.5. Configuration Option Format [RFC3241] ..............20 4.2.6. PROFILES Suboption [RFC3241] .......................21 4.3. Encapsulation of Header Compressed Packets ................22 4.4. Packet Reordering .........................................23 5. HC Pseudowire Setup Example ....................................24 6. Security Considerations ........................................29 7. Acknowledgements ...............................................29 8. IANA Considerations ............................................29 9. Normative References ...........................................30 10. Informative References ........................................31 11. Contributors ..................................................33 Ash, et al. Standards Track [Page 2] RFC 4901 Header Compression over MPLS Protocol June 2007 1. Introduction Voice over IP (VoIP) typically uses the encapsulation voice/RTP/UDP/IP. When MPLS labels [RFC3031] are added, this becomes voice/RTP/UDP/IP/MPLS-labels. MPLS VPNs (e.g., [RFC4364]) use label stacking, and in the simplest case of IPv4 the total packet header is at least 48 bytes, while the voice payload is often no more than 30 bytes, for example. When IPv6 is used, the relative size of the header in comparison to the payload is even greater. The interest in header compression (HC) is to exploit the possibility of significantly reducing the overhead through various compression mechanisms, such as with enhanced compressed RTP (ECRTP) [RFC3545] and robust header compression (ROHC) [RFC3095, RFC3095bis, RFC4815], and also to increase scalability of HC. MPLS is used to route HC packets over an MPLS label switched path (LSP) without compression/decompression cycles at each router. Such an HC over MPLS capability can increase bandwidth efficiency as well as the processing scalability of the maximum number of simultaneousShow full document text