Reinventing SIP
Work on the Session Initiation Protocol (SIP) began in 1996 and the first standards track specification (RFC 2543) was out in 1999. The expectation was that SIP, as a peer-to-peer protocol, would redefine the very nature of telecommunications. No longer would telephony depend upon a central agency — the “phone company.” Instead individuals would directly connect with other individuals. But a decade later SIP’s peer-to-peer story has been lost. VoIP is deployed but SIP’s impact has been limited.
Indeed, the biggest telecom story of the past 12 years has been the global adoption of mobile phones — over 3 billion of them in just 12 years — all using traditional circuit-switched telephony. And arguably, the most interesting telephony service enhancement, after mobility, has come fromSkype with its seamless integration of presence, instant messaging, wideband audio and video. But Skype is based on proprietary protocols, not SIP. And VoIP has helped drive down the cost of international calling, but this is the result of VoIP based on MGCP, H.248 or H.323 more than SIP, at least so far.
