There’s a new docmument authored by Tim Bosserman and myself that is a brief introduction to the SIP protocol on the SIP Wiki. As we say in the document:
The information here is not meant to replace the RFCs. It is not possible to duplicate all the information contained in 1000s of pages of RFCs in a few brief paragraphs.
We hope it gives an introduction to the main aspects of the protocol for the technically savvy reader:
http://www.toyz.org/cgi-bin/sipwiki.cgi?SipIntro.
It covers:
- The SIP URI
- Establishing a Call
- SIP Registration
- Frequently Misunderstood Aspects of SIP Protocol
- DNS Issues
- NAPTR Records
- SRV Records
- Resolving a SIP URI
- Phone Numbers, DNS, and SIP
- Introduction to ENUM
UPDATE: Can somebody please write a similar document for SIMPLE and the SUBSCRIBE/NOTIFY methods in practice?
