RFC 2508 (rfc2508) - Page 1 of 24
Compressing IP/UDP/RTP Headers for Low-Speed Serial Links
Alternative Format: Original Text Document
Network Working Group S. Casner
Request for Comments: 2508 Cisco Systems
Category: Standards Track V. Jacobson
Cisco Systems
February 1999
Compressing IP/UDP/RTP Headers for Low-Speed Serial Links
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 (1999). All Rights Reserved.
Abstract
This document describes a method for compressing the headers of
IP/UDP/RTP datagrams to reduce overhead on low-speed serial links.
In many cases, all three headers can be compressed to 2-4 bytes.
Comments are solicited and should be addressed to the working group
mailing list and/or the author(s).
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.
1. Introduction
Since the Real-time Transport Protocol was published as an RFC [1],
there has been growing interest in using RTP as one step to achieve
interoperability among different implementations of network
audio/video applications. However, there is also concern that the
12-byte RTP header is too large an overhead for 20-byte payloads when
operating over low speed lines such as dial-up modems at 14.4 or 28.8
kb/s. (Some existing applications operating in this environment use
an application-specific protocol with a header of a few bytes that
has reduced functionality relative to RTP.)
Casner & Jacobson Standards Track