The Session Initiation Protocol is a signaling protocol used for initiating, maintaining, and terminating real-time sessions that include voice, video and messaging applications.

What is SIP protocol and how it works?

Session Initiation Protocol (SIP) is the protocol of VoIP communication that allows users to make and receive calls over the internet. SIP works by sending messages from one SIP address to another. ... However, SIP also powers messages in the form of video calling and instant messaging.

What is SIP protocol used?

SIP is an application protocol used to carry all forms of digital media, including voice messages—so SIP is a specific technology that supports VoIP calls.