RTP is a protocol for delivering media stream end-to-end in real time over an IP network. Its applications include VoIP with SIP/XMPP, push to talk, WebRTC and teleconf, IOT media streaming, audio/video or simulation data, over multicast or unicast network services so on.
RTSP provides stream control features to an RTP stream along with session management.
RTCP, is also a companion protocol to RTP, used for feedback and inter-frame synchronization.
Receiver Reports (RRs) include information about the packet loss, interarrival jitter, and a timestamp allowing computation of the round-trip time between the sender and receiver.
Sender Reports( SR) include the number of packets and bytes sent, and a pair of timestamps facilitating inter-stream synchronization.
SRTP provides security by end-to-end encryption while SDP provides session negotiation capabilities.