This document specifies a payload format for generic Forward Error

Correction (FEC) for media data encapsulated in RTP. It is based on

the exclusive-or (parity) operation. The payload format described in

this document allows end systems to apply protection using various

protection lengths and levels, in addition to using various

protection group sizes to adapt to different media and channel

characteristics. It enables complete recovery of the protected

packets or partial recovery of the critical parts of the payload

depending on the packet loss situation. This scheme is completely

compatible with non-FEC-capable hosts, so the receivers in a

multicast group that do not implement FEC can still work by simply

ignoring the protection data. This specification obsoletes RFC 2733

and RFC 3009. The FEC specified in this document is not backward

compatible with RFC 2733 and RFC 3009.

Li Standards Track [Page 1]