Session Initiation Protocol (SIP) is a request-response protocol that defines interoperable implementations in handling call transfer and termination.
14:14 31 May 2017
Session Initiation Protocol (SIP0 was developed by the Internet Engineering Task Force to address the evolving needs of IP-based communications. It is a signaling protocol used for initiating, maintaining, modifying and terminating unified communications that involve voice, messaging, and video communication applications and services between two or more endpoints on IP networks.
Different types of multimedia SIP sessions include video conferencing and Internet telephony calls. SIP does not provide communication services but it can be used to invite participants to unicast or multicast sessions. It also supports name mapping and redirection services. Users and endpoints are detected with uniform service identifier using a syntax that resembles an email address. SIP can also be used for automatic callbacks, buddy lists, and message-waiting indicators.
SIP works in the application layer of the Open Systems Interconnection communications model. It is used to determine the end system to be used for the session, the media parameters, the communication media, and whether the called party agrees to engage in communication. In a nutshell, SIP is used for handling call transfer and termination.