RTSP

RTSP (Real-Time Streaming Protocol) acts as a network remote control, commanding streaming media servers to manage the delivery of real-time audio and video.

RTSP is an application-layer protocol: it controls the stream, but typically delegates the data transport to protocols like RTP (Real-time Transport Protocol). Think of it as a VCR remote for the network, using commands like SETUP, PLAY, PAUSE, and TEARDOWN to orchestrate a session. It operates on a client-server model, commonly using TCP port 554 for control. This protocol remains the cornerstone for many closed-circuit television (CCTV) and IP camera systems, providing the low-latency control necessary for live video surveillance and on-demand media access.

https://www.rfc-editor.org/info/rfc7826