The SIP Center
Commercial development portal with technical and market resources as well as a Session Initiation Protocol implementation test environment. http://www.sipcenter.com/
The Internet Engineering Task Force
The Internet Engineering Task Force (IETF) is a large open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet. It is open to any interested individual. http://www.ietf.org/
