First paragraph.

The activity related to SIP is probably larger at the moment than the activity of any other working group of the IETF. This is especially so when we connect it with the activity of a closely related working group called the "SIPPING" group. The first talks about the facilities to be included in the protocol as a basis for Session Initiation, and the second talks about the actual usage of the SIP protocol for particular applications.

References to these groups are

We are going to take a quick look at these to get an idea of the kinds of things this protocol involves.

The SIP tutorial by iptel.org shown in the references is often regarded as the best on the topic. We will look through a bit of it.

There are very full implementations of all sorts of SIP applications in Java. One of the first was the Java Advanced Intelligent Networking (JAIN) framework, done in conjunction with the National Institute of Standards and Technology (NIST).