Real-time voice along with video communication can be attained with the internet standard SIP (Session Initiation Protocol). That was initiated by the IETF (Internet Engineering Task Force) and you can find it in published form from RFC 3261. As for live communications, internet protocol “SIP” is used for establishing voice and video calls and within an IP network, one or more than one participant can whether create, alter, or end sessions with the help of this signaling protocol. It is very important in explanation of the functionality of the VoIP technology as one of the Voice over IP protocols. But at this point of learning about SIP, first you have to understand the term “session” within a communicating network. Actually, it is a clear-cut two-way phone call procedure. But in case of multi-media conference session, it can be consisted on loads of participating persons.