An RTP Payload Format for Generic FEC with Uneven Level Protection

Document Type Replaced Internet-Draft (individual)
Last updated 2009-02-24 (latest revision 2000-07-07)
Replaced by draft-ietf-avt-ulp
Stream (None)
Intended RFC status (None)
Expired & archived
plain text pdf html
Stream Stream state (No stream defined)
Document shepherd No shepherd assigned
IESG IESG state Replaced by draft-ietf-avt-ulp
Telechat date
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


This document specifies a payload format for generic forward error correction to achieve uneven level protection (ULP) of media encapsulated in RTP. It is an extension to the forward error correction scheme specified in RFC 2733 [1], and it is also based on the exclusive-or (parity) operation. The payload format allows end systems to transmit using arbitrary protection length and levels, in additional to using arbitrary block lengths. It also allows for the both complete recovery of the critical payload and RTP header fields, and partial recovery when complete recovery is not possible due to the packet lost situation. This scheme is backward compatible with non-FEC capable hosts, and hosts that are only capable of FEC schemes specified in RFC2733 [1], so that receivers which do not wish to implement ULP forward error correction can just ignore the extensions.


Adam Li (
Fang Liu (
John Villasenor (
Jeong Park (
Dong Park (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)