(RFC6354 published August 2011) Type names: audio, text Subtype names: fwdred Required parameters: rate: as defined in [RFC4102]. pt: as defined in [RFC4102]. forwardshift: An unsigned integer can be specified as the value. If this parameter has a value greater than '0', it indicates that the sender of this parameter will use forward-shifting with a base value as specified when sending out redundant data. This value is in RTP timestamp units. If this parameter has a value of '0', it indicates that the sender of this parameter will not use forward-shifting when sending its redundant data; i.e., the sender will have the same behaviors as defined in RFC 2198. Optional parameters: ptime: as defined in [RFC4102] [RFC8866]. maxptime: as defined in [RFC4102] [RFC4867]. Encoding considerations: This media type is framed binary data (see RFC 4288, Section 4.8) and is only defined for transfer of RTP redundant data frames specified in RFC 2198. Security considerations: See Section 6 of RFC 2198. Interoperability considerations: none. Published specification: RTP redundant data frame format is specified in RFC 2198. Applications that use this media type: It is expected that real-time audio/video, text streaming, and conferencing tools/applications that want protection against losses of a large number of consecutive frames will be interested in using this type. Additional information: none. Person & email address to contact for further information: Qiaobing Xie Intended usage: COMMON Restrictions on usage: This media type depends on RTP framing, and hence is only defined for transfer via RTP (RFC 3550 [RFC3550]). Transfer within other framing protocols is not defined at this time. Author: Qiaobing Xie Change controller: IETF Audio/Video Transport working group delegated from the IESG.