[h323plus] [Openh323-devel] help in creating WhiteBoard application using Opal

Simon Horne s.horne at packetizer.com
Tue Oct 30 00:49:10 EDT 2007

FYI opal is now opalVoIP and openH323 is continuing on as H323plus. OpenH323
(the project "in general" is no longer being actively developed.

T.120 support in Opal is at the same level it as it is in OpenH323 very very

There is a project on sourceforge which has been abandoned for many many
years based on OpenH323.

T.120 development in general has pretty much stopped for various reasons
including NAT issues. It uses TCP and you cannot easily use STUN,
H.460.18/19 or emerging NAT technologies like P2Pnat to traverse NATs.

That does not mean T.120 development has ceased.

In h323plus www.h323plus.org we have added H.239 support or extended video
to perform the same operation as T.120 app/whiteboarding would perform
except over UDP so it can traverse NATs. It utilises the existing video
plugin codecs to create a secondary video channel for the purpose of App
Sharing. This work is continuing with the addition of app sharing controls
such as H.249 collaberaton controls (remote userinputs, mouse movements and

T.124 or Generic conference controls has also been resurrected and is being
tunnelled through H.245 to perform "next generation" remote MCU control
functionality such as Inviting and ejecting participants, Floor and chair
controls and eventually the ability to introduce H.239 apps directly into
conferences as presentations.

If anyone would like to participate and/or contribute to this work then
please let me know.


 -----Original Message-----
From: openh323-devel-bounces at lists.sourceforge.net
[mailto:openh323-devel-bounces at lists.sourceforge.net]On Behalf Of Vishak V.
Sent: Monday, 29 October 2007 3:08 PM
To: openh323-devel at lists.sourceforge.net
Subject: [Openh323-devel] help in creating WhiteBoard application using Opal

            I am Vishak. I want to develop a white board application for
linux using gtk. I heard that whiteboard applications use T.120 protocol.
T.120 protocol is in the stack of Opal. So can any one please tell me how
create a whiteboard application.


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