The GNU Gatekeeper (GnuGk) is a full featured H.323 gatekeeper, available freely under GPL license. It forms the basis for a free IP telephony (VOIP) or video conferencing system.

Please read the manual (especially the tutorial) and the FAQ for general information what a gatekeeper does or take a look at some VOIP and H.323 books to get into the subject.

Features

• we provide executables for Linux, Windows, MacOS X, Solaris, FreeBSD, OpenBSD and NetBSD
• can run as a Windows service
• accounting and call authorization via SQL database, Radius, file or external application
• database drivers for ODBC, MySQL, PostgreSQL, SQLite and Firebird
• flexible call routing
• number rewriting (calling and called)
• support for NAT traversal (H.460.18/H.460.19, H.460.23/H.460.24 or own method)
• full H.323 proxy
• IPv6 support (incl. IPv4-IPv6 proxying)
• TCP interface to applications
• CTI functions (eg. VOIP call-center, call transfers)
• gatekeeper clustering support (neighbors, parent/child, alternates)
• H.235 security
• LDAP directory support (H.350)
• graphical user interface
• it's free, including source code

There are also lots of ideas for new features.

Support

Professional (paid) support is available directly from the authors of GnuGk. Please contact Jan Willamowius at jan@willamowius.de for more information or use the contact form.

Compatibility

In addition to the general settings explained in the manual there are some specific configuration notes how to configure gateways from some major vendors for use with GnuGk.