● MCU to MCU
Cascading Between Two MCUs Using an ISDN-video Link
In this topology, an ISDN-video participant from conference running on MCU A calls a conference
running on MCU B over an ISDN-video link.
Guidelines for ISDN-video Cascaded Links
● Content is restricted, in the sense that when another endpoint wants to send content, the first
endpoint must stop sending content before the second endpoint can initiate or send content.
● Endpoints that do not support H.239 can receive the Content using the Send Content to Legacy
Endpoints option.
● A participant joining a conference with active Content, cannot view it. Content sharing should be
restarted.
● Cascaded MCUs/Gateways must be registered with the same Gatekeeper or neighboring
Gatekeepers. MCUs and endpoints must also be registered with Gatekeepers.
● Gateway/MCU calls require definition of IVR Services. For more information see
Configuration.
Note: Content Protocol over ISDN-video Cascaded link
The content sharing protocol is H.263 when sent over ISDN-video Cascading link.
Gateway to Gateway Calls via ISDN-video Cascading Link
When H.323 participants connects to another IP participants via a Gateway to Gateway call over an
ISDN-video link, the dialing string includes the following components:
[GW A prefix in GK] - The prefix with which the Collaboration Server (gateway) is registered to the
gatekeeper.
[GW Profile ID] - The ID of the Gateway Profile defined on Gateway A to be used for routing the call to
the Gateway B.
[GW Profile ISDN (audio/video) number] - The dial-in number assigned to the Gateway Profile
defined on Gateway B, including the required country and area codes.
Information required that is not part of the dialing string:
Polycom, Inc.
Cascading Conferences
System
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