RTCPprotokollan

RTCPprotokollan, or Real-time Transport Control Protocol, is a companion protocol to RTP (Real-time Transport Protocol). While RTP is responsible for the actual transmission of real-time data such as audio and video, RTCP is used to monitor the quality of service provided for the data delivered by RTP. It provides out-of-band control information for an RTP session.

The primary functions of RTCP include providing reception quality feedback, synchronizing multiple media streams, and identifying participants in a session. It does this by periodically sending control packets to all participants in an RTP session. These packets contain information such as the sender's synchronization source (SSRC) identifier, packet loss statistics, jitter, and round-trip delay. This feedback allows applications to adapt their transmission rates or other parameters to improve the perceived quality of the real-time media.

RTCP packets are typically sent at a lower rate than RTP packets, usually around 5% of the session bandwidth. This ensures that the control traffic does not significantly impede the flow of real-time data. By collecting and analyzing the RTCP reports, applications can make informed decisions to manage the real-time communication effectively. Without RTCP, RTP sessions would lack the necessary mechanisms for quality monitoring and control, making them less robust and adaptable to changing network conditions.