sipXtapi is a comprehensive client library and software development kit (SDK) for SIP-based user agents. It includes SIP signalling support as well as a media framework. A complete and very feature rich softphone can be built easily by adding a graphical user interface on top of sipXtapi. Alternatively, sipXtapi was engineered to be embedded into existing applications adding real-time communications to such applications.

sipXtapi have full featured, well tested voice processing framework, and video processing framework will be available in near future. The sipX SIP stack fully supports all relevant SIP RFCs; in particular a very extensive framework for firewall and NAT traversal. The media framework is the same used by the sipX media server.

The sipXtapi SDK is a C application programming interface for real-time voice and video communications over IP. Specifically, sipXtapi provides a generalized interface for real-time communications on top of the Session Initiation Protocol (SIP), RFC 3261, and the real-time Transport Protocol (RTP), RFC 1889. While the SIP and RTP protocols provide signaling and media transport infrastructure, sipXtapi includes many additional protocols and standards implementations needed for voice and video communications.

sipXtapi is developed in open source and hosted as part of the sipX line of projects available from SIPfoundry. It is licensed under LGPL, which allows commercial usage of the library without the viral infection commonly associated with GPL. Essentially, you may use the code as-is and build on top of it without exception, however, if you modify the existing code (e.g. bug fix or feature enhancement), you must make changes available under LGPL. For more information on open source licensing, please see www.opensource.org .

The original technology was donated to SIPfoundry by Pingtel Corp in March of 2004 when Pingtel decided to adopt an open source business model. The sipXtapi technology is considered well tested and very interoperable with other SIP devices.

NOTE: The library definition and source code for sipXtapi is contained within the sipXcallLib project.

Platform Support

sipXtapi is primarily developed under WIN32; however, sipXtapi can be built and used under Linux and MacOs X. WinCE support is in development. 

License

sipXtapi is distributed under the Lesser General Public License (LGPL).

Documentation

• General description, features, usage and methodologies .

Communications

Mailing List

Issue Tracking

NOTE: The latest sipXtapi source code is available from sipXtapi svn branch.

Before checking out this project, please learn about subversion by reading the Using subversion at SIPfoundry page. Subversion is a great source control system, however some things are non-obvious (e.g. meta data and CRs/LFs).

Source control for all sipX projects share a single subversion repository. Instructions on how to check out and build the code are on this wiki page.

Please also read this readme.txt for build instructions.

Contributing

Project Coordinator:

Bob Andreasen

Committers

Alexander Chemeris
Daniel Petrie
Keith Kyzivat
Mike Cohen
-- Your name here --

In order to contribute code or other source material to the sipXcallLib project, you must first execute the SIPfoundry Contributor Record or Agreement ; yes, we know that other projects don't always do this.

Suggestions for sipXtapi contributors

These are some sipXtapi areas that need help. If there are other contributions you'd like to make, please don't be shy - get on the mailing list and discuss them.

• Complete Linux support: sipXtapi builds and runs under linux; however, not all of the audio support is included. In particular, the volume control and the ability to select audio devices is missing. If you are interested in helping, please send an email to the sipxtapi-dev mailing list.
• sipXtapi enhancement: What feature/API do you need?
• Examples: Can you share with your sipXtapi usage examples?
• Documentation / Code cleanup: All help appreciated
• More wishes are listed on sipX wiki.