RFC 3545 (rfc3545) - Page 1 of 22


Enhanced Compressed RTP (CRTP) for Links with High Delay, Packet Loss and Reordering



Alternative Format: Original Text Document



Network Working Group                                           T. Koren
Request for Comments: 3545                                 Cisco Systems
Category: Standards Track                                      S. Casner
                                                           Packet Design
                                                          J. Geevarghese
                                         Motorola India Electronics Ltd.
                                                             B. Thompson
                                                                P. Ruddy
                                                           Cisco Systems
                                                               July 2003


       Enhanced Compressed RTP (CRTP) for Links with High Delay,
                      Packet Loss and Reordering

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 a header compression scheme for point to
   point links with packet loss and long delays.  It is based on
   Compressed Real-time Transport Protocol (CRTP), the IP/UDP/RTP header
   compression described in RFC 2508.  CRTP does not perform well on
   such links: packet loss results in context corruption and due to the
   long delay, many more packets are discarded before the context is
   repaired.  To correct the behavior of CRTP over such links, a few
   extensions to the protocol are specified here.  The extensions aim to
   reduce context corruption by changing the way the compressor updates
   the context at the decompressor: updates are repeated and include
   updates to full and differential context parameters.  With these
   extensions, CRTP performs well over links with packet loss, packet
   reordering and long delays.









Koren, et al.               Standards Track