SIP
SIP (Session Initiation Protocol) is an application-layer signaling protocol used to establish, modify, and terminate multimedia communication sessions over IP networks. It is widely used for Voice over IP (VoIP) calls, video conferencing, instant messaging, and other real-time communication services. SIP operates independently of the underlying transport protocol and works in conjunction with other protocols like SDP (Session Description Protocol) to negotiate session parameters.
Developers should learn SIP when building or integrating real-time communication systems such as VoIP applications, video conferencing platforms, or unified communications solutions. It is essential for implementing call setup, presence, and instant messaging features in enterprise and consumer applications, and is widely adopted in telecommunications and webRTC-based services.