Sidewinder G2 6.1.2 Administration Guide - Glossary of Technical ...

About the T.120 proxy
Chapter 9: Configuring Proxies
Notes on selected proxy configurations
The T.120 proxy provides support for applications built using the International
Telecommunication Union (ITU) T.120 recommendations. The T.120
recommendations are most prevalent in data conferencing applications. T.120
defines several standardized data conferencing services including application
sharing, text chat, shared whiteboard, and multipoint file transfer.
Microsoft’s NetMeeting is a popular example of a T.120 enabled application.
The T.120 proxy enables you to use all of the standard T.120 data conferencing
services, and provides you with a means to control which services are
accessible. The T.120 proxy also provides support for the Microsoft
NetMeeting chat and application sharing, which are non-standard T.120
application services.
Note: The audio, video, ILS, and ULS features of NetMeeting are not supported by
the T.120 proxy. To provide support for these features, you must enable the H.323
proxy. You must also add the pre-configured NetMeeting proxy rule to the active
proxy rule group. This will ensure that both proxies remain in synchronization with
one another. See “Synchronizing the T.120 and H.323 proxies for use with
NetMeeting” on page 265 for more information.
When configured, the T.120 proxy is transparent to the participants of the data
conference. The T.120 proxy will come into play when a conference participant
attempts to join an existing conference or attempts to invite another participant
that resides in a different burb. The T.120 proxy will intercept and mediate the
session between the pair of conference host machines (referred to as "nodes"
in T.120 parlance).
T.120 conferences are arranged into a hierarchy of nodes. The placement of
the Sidewinder G2 with respect to the nodes in the conference affects how
many sessions are created through the proxy and the communication path of
the conference data. When a first conference participant joins a conference in
a different burb, a T.120 session will be created between the participant's node
and the contacted node. If a second conference participant attempts to contact
the new conference node, a separate session will be created.
The preconfigured NetMeeting proxy rule (when added to the active rule
group) will apply to each participant’s respective node IP address. On the other
hand, if the second participant contacts the first participant and asks to join the
conference, the same session through the proxy will be used. The NetMeeting
proxy rule, which applies to the first participant’s node will also apply to this
session.
The T.120 proxy is configured to use port 1503 by default. This can be changed
as described in “Configuring proxies” on page 266.
263