Per the SIP forum , SIP (Session Initiation Protocol) has “emerged as the protocol of choice for setting up conferencing, telephony, multimedia and other types of communication sessions on the Internet. SIP may also be used for new types of communications, such as instant messaging and application level mobility across various networks, including wireless, and across user devices.” SIP trunking today is much more than a telephony solution that lowers costs. It is the foundation for unified communications and fixed mobile convergence (FMC). Ultimately, it is about presence, and it is central to the IT communications environment. I call this the 2nd Generation of SIP Trunking. More...