(RFC 5109 published December 2007, subtype last updated December 2007)

Type name: video

Subtype name: ulpfec

Required parameters:

rate: The RTP timestamp rate that is used to mark the time of
   transmission of the FEC packet in a separate stream.  In cases in
   which it is sent as redundant data to another stream, the rate
   SHALL be the same as the primary encoding it is used to protect.
   When used in a separate stream, the rate SHALL be larger than 1000
   Hz to provide sufficient resolution to RTCP operations.  The
   selected rate MAY be any value above 1000 Hz, but is RECOMMENDED
   to match the rate of the media this stream protects.

Optional parameters:

onelevelonly: This specifies whether only one level of FEC protection
   is used.  The permissible values are 0 and 1.  If 1 is signaled,
   only one level of FEC protection SHALL be used in the stream.  If
   0 is signaled, more than one level of FEC protection MAY be used.
   If omitted, it has the default value of 0.

Encoding considerations: This format is framed (see Section 4.8 in
the template document [3]) and contains binary data.

Security considerations: The same security considerations apply to
these media type registrations as to the payloads for them, as
detailed in RFC 5109.

Interoperability considerations: none

Published specification: RFC 5109

Applications that use this media type: Multimedia applications that
seek to improve resiliency to loss by sending additional data with
the media stream.

Additional information: none

Person & email address to contact for further information:
   Adam Li adamli&hyervision.com
   IETF Audio/Video Transport Working Group

Intended usage: COMMON

Restrictions on usage: This media type depends on RTP framing, and
hence is only defined for transfer via RTP [1].  Transport within
other framing protocols SHALL NOT be defined as this is a robustness
mechanism for RTP.

Author:
   Adam Li adamli&hyervision.com

Change controller:  IETF Audio/Video Transport Working Group
   delegated from the IESG.