Open H323

Features, tools and basic utilization

Liane Tarouco

Leandro Bertholdo

Open H323 – Project

It appeared from 1998 trying to solve the problem of the high cost of licenses for commercial implementation of the protocol.

These costs was hindering its development and use in the community of the Internet.

Open H323 – Project

The OpenH323 project aims to create a full featured, interoperable, Open Source implementation of the ITU-T H.323 teleconferencing protocol that can be used by personal developers and commercial users without charge

Open H323 - Project

Developed in C++ Ported to several operational systems like

Windows, FreeBSD, Solaris and Linux (Redhat, Debian, Fedora, etc.).

Several tools implemented are available in http://www.openh323.org.

Spanish tutorial at http://toncar.cz/openh323/tut/sp/files.html

OpenH323 x H323

In terms of concepts and functionalities, does not exist significant difference in protocols implementations.

Implementation uses the same standards that base the H323, as well as terminals, gatekeepers, and control units multipoint (MCUs).

The hierarchy of class of the OpenH323 can be reached in http://www.openh323.org/docs/OpenH323/HIER.html

Open H323 Tools

Several tools are ready to run:

OhPhone H.323 interactive line command client. Supports audio and video; no shared whiteboard, file transfer, or shared applications.

OpenAM: H.323 answering machine. Plays back a recorded message and records incoming audio. No video support at present.

Forwarder: Forwards H.323 sessions from one IP address/port to another. Used to serve multiple H.323 destinations from a single IP address.

Open H323 Tools

OpenMCU: Multipoint Control Unit. Connects multiple sessions together into a conference call (Videoconference Server).

PSTNGw: Allows NetMeeting clients to make phone calls onto the conventional phone system - the Public Switched Telephone Network (PSTN). Requires special hardware.

OpenIVRH: H323 Interactive Voice Response

OpenGK H.323 gatekeeper

CallGen323: H.323 call generator

GnomeMeeting: Same as microsoft Netmeeting without full T.120 protocol.

Installing OpenMCU

OpenMCU package was tested on FreeBSD and Linux (Fedora and Debian)

FreeBSD instalation is very easy:# pkg_add –r openh323# pkg_add –r openmcu# make install# /usr/local/bin/openmcu –n -v

NOTE: If you are using FreeBSD 5.x, you have to install a compat4x package before.

OpenMCU Features

OpenMCU has features like– Audio codec G.711, GSM MS-GSM e LPC-10– Video codec H.261– Can accept multiples connections

simultaneously– Several different conferences can be talking

place at the same time using “room” feature.– display statistics on call in progress

OpenMCU Features

– You can do a loopback audio to test your signal quality

– You can permit/force/disable gatekeeper utilization

– You can trace all calls– Support until four (4) videos at the same time.

You can hear another people but only four can send a video signal.

Testing OpenMCU with Netmeeting

Netmeeting and Gnomemeeting interfaces.

OpenMCU Logs

Waiting for incoming calls for "OpenH323 MCU v1.1.7"Command ? Opening connectionAccepting call from Leandro Bertholdo [192.168.1.11] using

Microsoft<AE> NetMeeting<AE>/3.0 with room id room101Member ip$192.168.1.11:2422/25581 will not hear their own voiceStarted logical channel: sending G.711-uLaw-64k{sw} <3>Started logical channel: sending H.261-QCIF <9>Started logical channel: receiving G.711-uLaw-64k{sw} <5>Opening connectionIncoming H.323 call from Linux Bertholdo [192.168.1.17] has not

selected a room.Using room room101 as the default.Accepting call from Linux Bertholdo [192.168.1.17] using

gnomemeeting/1.2.1 (OpenH323 v1.15.3) with room id room101