The support real-time applications such as video conferencing or telephone speech, is the challenge to the Internet. These applications require qualities Service as conventional Internet protocols can not offer. RTP was designed to try to solve this problem, which is more directly in a multipoint environment, in paying for both the management of real-time administration multipoint session.
To achieve this, two intermediate are required, translators and mixers. A translator operable to translate an encoded application in a certain format another format better suited to passing through a subnet. For example, an application MPEG coded video conferencing could be decoded and recoded in H.261 to reduce the amount of information transmitted. A blender’s role is to consolidate several applications corresponding to several distinct streams into one stream keeping the same format. This approach is particularly interesting for the flow of words digital.
RTCP accept five types of packages:
• 200: REPORT SENDER (ratio of the issuer);
• 201: REPORT RECEIVER (Receiver Report);
• 202: SOURCE DESCRIPTION (source description);
• 203: BYE (goodbye);
• 204: APPLICATION SPECIFIC (specific application).
These packages give different network nodes instructions for a better control of real-time applications.