2190: RTP Payload Format for H.263 Video Streams.

This document specifies the payload format for encapsulating an H.263 bitstream in the Real-Time Transport Protocol (RTP). Three modes are defined for the H.263 payload header. An RTP packet can use one of the three modes for H.263 video streams depending on the desired network packet size and H.263 encoding options employed. The shortest H.263 payload header (mode A) supports fragmentation at Group of Block (GOB) boundaries. The long H.263 payload headers (mode B and C) support fragmentation at Macroblock (MB) boundaries.