Illustrated TCP/IP by Matthew G. Naugle Wiley Computer Publishing, John Wiley & Sons, Inc. ISBN: 0471196568   Pub Date: 11/01/98

Chapter 206
Translators

The RTP protocol is open, which allows for many different encoding schemes to be used. This provides many advantages. Some protocol schemes are better used in different topologies than others. Mixers and translators are used to compensate for differences in encoding schemes, and transmission and reception rates. Translators and mixers reside in the middle of a multimedia network, and are network attachments like any other attachment. Their application makes them reside logically between senders and recipients and they process the RTP information as they receive it and then retransmit the information. The translator functions are the easiest to explain, so we will start there.

As shown in the slide, a translator simply translates from one payload format to another. Take the example of a network station that would like to participate in a stream but is located beyond a WAN link that provides very little bandwidth. The high-speed workstations could simply reduce their capabilities to provide for the low-bandwidth link, but with the translator they do not have to. The translator can simply receive the high-bandwidth signal and translate it to a low-bandwidth signal for the remote network station. In this way, receivers of high-quality links can continue using them, while receivers of low-bandwidth links participate as well.

Translators