Barrett Lyon has created a don't miss resource that shows you how to configure P2P SIP URI (Uniform Resource Identifier) dialing on your Asterisk-based PBX. "There are thousands of people that operate ...

The iptel.org 180+ page SIP tutorial is outstanding. Another overview that is a bit more market-oriented and nearly as long. White paper on the SIP value proposition over telephony, SIP and the new ...