jSIP looks to implement the Session Initiation Protocol, a text-based protocol for initiating collaborative sessions between users. SIP has been designated by the IETF as an Internet protocol, with its specifications in RFC 2543. In addition to building the SIP protocol as specified, jSIP will look to provide prototype implementations of some of the SIP extensions, most notably for Instant Messaging.
4/3/2002 NEW!!! SipChat -- SIMPLE IM client based on jSIPI've just made available SipChat, an IM client that I've been working on the last few months. Based on the "SIP for Instant Messaging and Presence Leveraging Extensions" (SIMPLE) drafts, I was looking to create a simple instant messaging client with which I could do some prototyping (such as IM across NATs and Firewalls, using digital signatures, etc). Fortunately, I had a very nice GUI from John Ramsdell and Galen Williamson here at MITRE (http://simp.mitre.org) to start from. Replacing their SIMP backend model with jSIP and adding some capabilities to the jSIP library allowed me to get a client working relatively quickly. They've got some new stuff in their client (such as group communications) that would be very nice to add into this also.
To get the SipChat client, go to the Download page
Why create jSIP?
When I first started this project, I couldn't find an Open Source version of the SIP stack implemented in Java. Since I wanted to try and build some prototypes using this new protocol, and having more experience with Java than C++, I decided to build my own.
Instead of starting from scratch, I took a copy of dissipate, a simple SIP stack using C++ and converted it to Java. From there I've greatly expanded and enhanced jSIP to work within the Java framework. Although still very much a work-in-progress, hopefully it will be useful for developing prototype SIP applications.
The SIP: Session Initiation Protocol page is probably the best resource on SIP from one of its original co-authors.
Jonathan Rosenberg's Home Page is a page from another SIP co-author and has links to documents produced by the SIP for Instant Messaging and Presence Leveraging (SIMPLE)'s working group.
The SIP Center has information about many of the commercial offerings available that implement SIP.
The SIP Forum promotes awareness and provides information about the capabilities of SIP
If you have any questions or comments about jSIP, you can contact me here