RFC 2198 (rfc2198) - Page 1 of 11

RTP Payload for Redundant Audio Data

Network Working Group                                        C. Perkins
Request for Comments: 2198                                  I. Kouvelas
Category: Standards Track                                     O. Hodson
                                                             V. Hardman
                                              University College London
                                                             M. Handley
                                                                    ISI
                                                             J.C. Bolot
                                                         A. Vega-Garcia
                                                       S. Fosse-Parisis
                                                 INRIA Sophia Antipolis
                                                         September 1997


                  RTP Payload for Redundant Audio Data

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.

Abstract

   This document describes a payload format for use with the real-time
   transport protocol (RTP), version 2, for encoding redundant audio
   data.  The primary motivation for the scheme described herein is the
   development of audio conferencing tools for use with lossy packet
   networks such as the Internet Mbone, although this scheme is not
   limited to such applications.

1  Introduction

   If multimedia conferencing is to become widely used by the Internet
   Mbone community, users must perceive the quality to be sufficiently
   good for most applications.  We have identified a number of problems
   which impair the quality of conferences, the most significant of
   which is packet loss.  This is a persistent problem, particularly
   given the increasing popularity, and therefore increasing load, of
   the Internet.  The disruption of speech intelligibility even at low
   loss rates which is currently experienced may convince a whole
   generation of users that multimedia conferencing over the Internet is
   not viable.  The addition of redundancy to the data stream is offered
   as a solution [1].  If a packet is lost then the missing information
   may be reconstructed at the receiver from the redundant data that
   arrives in the following packet(s), provided that the average number



Perkins, et. al.            Standards Track