Session Initiation Protocol (SIP) is a fundamental building block that service providers can use to harness the power of the Internet Protocol and transform their traditional revenue streams.
The world of networking is undergoing a sea of change: fixed and mobile networks are converging; computing and communications are becoming inseparable. The ubiquity of IP is transforming the data infrastructure into an all-encompassing communications capability that overshadows the PSTN. At the center of this evolution is SIP: it is the mechanism that unites services across platforms, thus creating a multiplicity of new possibilities.
SIP carries the banner of Internet-style innovation into the traditional world of telco voice services. With SIP, services can be created that combine elements from telephony and other web applications such as email, messaging, the Internet and video streaming. The use of open Application Programming Interfaces (APIs) mean that ISPs, ASPs and even end-users can programme their own services.
SIP achieves all this by establishing, modifying and terminating "sessions" over IP networks. These sessions could be as basic as a telephone call or as complex as a multi-party mixed media session. SIP doesn't care: it specifies only what is needed.