This is the manual for GNU Gatekeeper 5.13.
A manual for your version is in your GnuGk download archive.
A PDF version can be found in the download section.

Chapters: Contents · Introduction · Installation · Getting started · Basic Config · Routed Mode & Proxy · Routing · RAS Config · Authentication · Accounting · Neighbors · Per Endpoint Config · Advanced Config · Monitoring · Advanced Topics

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The GNU Gatekeeper Manual Chapter 1

1. Introduction

1.1 About

The GNU Gatekeeper is an open-source project that implements a H.323 gatekeeper. A gatekeeper provides call control services to H.323 endpoints and is an integral part of most telephony or video conferencing installations that are based on the H.323 standard.

According to the H.323 standard, a gatekeeper shall provide the following services:

  • Address Translation
  • Admissions Control
  • Bandwidth Control
  • Zone Management
  • Call Control Signaling
  • Call Authorization
  • Bandwidth Management
  • Call Management

The GNU Gatekeeper implements all of these functions and a number of additional features. For the protocol handling and encoding and decoding of the messages, it uses the H323Plus library (a continuation of the now defunct OpenH323 project).

H.323 is an international standard published by the ITU. It is a communications standard for audio, video, and data over the Internet. See also Paul Jones' A Primer on the H.323 Series Standard.

1.2 Copyright

The GNU Gatekeeper is covered by the GNU General Public License version 2 (GNU GPL v2). In addition, we explicitly grant the right to link this code to the OpenH323/H323Plus and OpenSSL library.

Some protocols implemented in the GNU Gatekeeper are covered by patents (especially the firewall / NAT traversal protocols). To the best of our knowledge, the GNU Gatekeeper Project has a valid license for all its releases, but users making derived versions of this code must ensure that they have a valid license before enabling those features.

The GNU Gatekeeper contains H.460.18 and H.460.19 technology patented by Tandberg and licensed to the GNU Gatekeeper Project. It also also contains patented H.460.23 and H.460.24 technology licensed to the GNU Gatekeeper Project.

Generally speaking, the GNU GPL allows you to copy, distribute, resell or modify the software, but it requires that all derived works must also be published under the GNU GPL. This means that you must publish full source for all extensions to the gatekeeper and for all programs where you incorporate code from the GNU Gatekeeper. See the file COPYING for details.

If that's not what you want, you must interface to the gatekeeper through the status port and communicate with it via TCP. This allows you to integrate basic functionality into the gatekeeper (and provide source for that) but keep other parts of your application private.

1.3 Name

The full name of this project is GNU Gatekeeper, but it may also be referred to as GnuGk. The use of "GNU" in the name is to emphasize that this is free software. Early versions were called the OpenH323 Gatekeeper.

1.4 Download

The newest version is available at the download page.

The very latest source code is in the git repository. Beware - that's the bleeding edge.

You can also download executables for a number of operating systems from the download page.

1.5 Mailing Lists

There is a mailing list for the project:

Please subscribe here.

1.6 Contributors

The project founder and current maintainer is Jan Willamowius <[email protected]>

Over the years many people have contributed, most notable Simon Horne, Michal Zygmuntowicz and Chih-Wei Huang.

Next Previous Contents

Chapters: Contents · Introduction · Installation · Getting started · Basic Config · Routed Mode & Proxy · Routing · RAS Config · Authentication · Accounting · Neighbors · Per Endpoint Config · Advanced Config · Monitoring · Advanced Topics


Last updated: 21. Jan 2025