He used a new VoIP technology called SIP (Session Initiation Protocol).

The most common method is to use SIP (Session Initiation Protocol) and Mobile IP.

Some application servers target networks other than web-based ones: Session Initiation Protocol servers, for instance, target telephony networks.

Most softphone clients run on the open Session Initiation Protocol (SIP) supporting various codecs.

This became possible with the introduction of the Session Initiation Protocol (SIP).

For call signaling it employs the Session Initiation Protocol (SIP).

Session Initiation Protocol (SIP) (only chat at present)

Anyone within range of one of the routers can make phone calls using a Wi-Fi or SIP (Session Initiation Protocol) telephone.

The Session Initiation Protocol (SIP) specification RFC 2543 is released.

X-Lite is a proprietary freeware VoIP soft phone that uses the Session Initiation Protocol.