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GnuComm – GNU Telephony

GNU Telephony development has moved to

What are GnuComm and GNU Telephony?

GnuComm is the Telecom subsystem of the GNU Project. The goal of GnuComm is to deliver scalable telephony services for current and next generation telephone networks using entirely free software on the GNU system.

GnuComm currently includes 7 GNU projects: Bayonne, SIP Witch, and their supporting libraries (Common C++ / uCommon, ccAudio, ccScript, ccRTP, and ZRTP / ZRTP4J). The menu provides quick access to the web pages of the corresponding packages, and to download information for stable releases and additional recommended files.

Since 2006, these components have been developed through GNU Telephony.

GNU Telephony is a project to enable anyone to use free (as in freedom) software for telephony, and with the freedom to do so on any platform they choose to use. We also wish to make it easy to use the Internet for real-time voice and video communication, and in fact for all forms of real-time collaboration. Finally we wish to make it possible to communicate securely and in complete privacy by applying distributed cryptographic solutions. Our goal is to enable secure and private real-time communication worldwide over the Internet that is free as in freedom, and is also free as in no cost too!
[From the main page of, archived at the Wayback Machine]

What is GNU SIP Witch?

GNU SIP Witch is a secure peer-to-peer VoIP server that uses the SIP protocol. Calls can be made peer-to-peer behind NAT firewalls*, and without needing a service provider. GNU SIP Witch supports using secure telephone extensions, for placing and receiving calls directly over the Internet, and intercept-free peer-to-peer audio and video extensions. GNU SIP Witch also is being introduced as a desktop VoIP mediation service to enable the construction of participatory bottom-up secure calling networks and to enable replacement of Skype with free software and published protocols. As a desktop mediation service, GNU SIP Witch can solve issues like NAT* in one place for all user agents, and offer new ways to route and redirect VoIP much like gstreamer does for desktop media. (* Work in progress.)
[From the main page of, as archived in March 2012]

What is GNU Bayonne?

GNU Bayonne is the telephone server of the GNU Project. It offers scalable media and scripted voice application services for SIP and H.323 networks as well as for traditional PSTN and ISDN services. GNU Bayonne may be used standalone to deliver carrier-hosted or premise application services behind existing switching equipment and standard compliant VOIP platforms, or together with GNU SIP Witch to offer complete VOIP phone systems.

GnuComm / GNU Telephony Development

The following documents reflect the main periods of GnuComm / GNU Telephony development. Many of them were retrieved from and (archived). You will also find a wealth of information on the Events & Articles page, notably historical overviews in David Sugar's slide presentations at the ClueCon 2005 (Bayonne), and the LibrePlanet 2012 (GNU Telephony).

Mailing Lists and Other Resources

The canonical set of GNU mailing lists have been set up for GnuComm: