iptel.org offers in-depth resources on SIP, the Session Initiated Protocol, as well as
related protocols. The resources found here are both focused on understanding SIP and
on practical resources for the SIP practitioner.
The SIP Introduction is a practical
introduction to the SIP protocol, including visual displays of how the protocol works.
A comprehensive tutorial to the SIP
protocol (downloadable in Adobe Acrobat format).
The product database lists SIP-relatedi products. Any user or manufacturer can
add a product to the database.
List of free SIP software provided by iptel.org and third parties.
Other Useful Sites
- SIP site --
maintained by SIP author, Henning Schulzrinne
- http://www.tech-invite.com/ -- excellent website with many detailed
information including call-flows
- Packetizer's SIP
site (very useful, still use with caution -- website maintained by advocates of
formerly competing technology, H.323)
- SIP Phoenix
Group --A good site with different categories of research papers on
- Voip-Info -- large wiki around all topics VoIPi