RTP stands for Real-time Transport Control Protocol.
RTCP is defined in IETF RFC 3550. It is used alongside RTP.
RTCP offers a lightweight control mechanism for RTP that can be used to send statistic reports and flow control messages.
These main two uses enable the receiver to provide feedback to the sender who can then deduce the network’s status and accommodate to it (by changing the bitrate or adding FEC).
