RTP: Audio and Video for the Internet

This chapter has described the fundamental behavior of RTP senders and receivers in some detail, focusing especially on the design of the receiver's playout buffer. The playout buffer design is relatively simple for streaming applications, which can accept several hundred milliseconds (or perhaps even seconds) of delay. For applications designed for interactive use, however, the play-out buffer is critical to achieving good performance. These applications need low latency, and hence playout buffer delays of a few tens of milliseconds , taxing the design of algorithms that must balance the needs of low delay with the need to avoid discarding late packets if possible.

RTP systems place a lot of intelligence in the end systems, leaving them to compensate for the variability inherent in a best-effort packet network. Recognizing this is the key to good performance: A well-designed, robust implementation can perform significantly better than a naive design.