User's Manual
Chapter 4-Additional Conferencing Information
Polycom, Inc. 4-63
Content Display on Legacy Endpoints in Telepresence Conferences
When Content is sent to legacy endpoints in Telepresence conferences, their video layout 
automatically changes to a “Content layout” which is defined by the system flag 
LEGACY_EP_CONTENT_DEFAULT_LAYOUT. If MLA is managing the Telepresnce 
layout prior to Content being sent, the MCU takes over managing the layout of Legacy 
endpoints once Content is started. The video layouts of the other conference participants 
continue to be managed by MLA. 
If MLA was managing the Telepresence layouts, when Content ends, control of the layouts 
for legacy endpoints goes back to the MLA after a short time. 
Multiple Cascade Links
Multiple Cascade Links enable Cascading between RMXs hosting conferences that include 
Immersive Telepresence Rooms (ITP) such as Polycom’s OTX and RPX Room Systems.
In previous versions the video stream of only one of the ITP endpoints could be sent to the 
remote RMX.
Guidelines
• Multiple Cascade Links are implemented by creating a Link Participant which consists of a 
main link and sub-links which are automatically generated and sequentially numbered.  
For more information see "Creating a Link Participant” on page 4-67.
• All cascaded links must use H.323 protocol.
• Multiple Cascade Links are supported with MPMx and MPM+ cards.
• Multiple Cascade Links are supported in CP conferencing mode.
• The number of cascading links is defined manually according to the maximum number 
of Room System cameras in the cascaded conference.
• When the active speaker is in an Immersive Telepresence Room, Multiple Cascade Links 
are used, one link for each of the Room System’s cameras.
— An RPX 4xx Room System requires 4 Cascaded Links to carry the video of its 4 
cameras.
— An RPX 2xx Room System requires 2 Cascaded Links to carry the video of its 2 
cameras.
— An OTX 3xx Room System requires 3 Cascaded Links to carry the video of its 3 
cameras. The OTX Room System must be configured as Room Switch in order to 
send multiple streams. When configured in CP Mode, its cameras zoom out and all 
3 screens are sent as one stream.
• The number of links is defined when creating the Link Participant. Each conference in 
the cascade must have a Link Participant with the same number of Multiple Cascade Links 
defined. Calls from Link Participants not defined with the same number of links are 
rejected. Number of cascading links is not identical for all conferences is listed as the Call 
Disconnection Cause. For more information see "Creating a Link Participant” on page 4-67 
and "Monitoring Multiple Cascade Links” on page 4-69.
• Although it is possible to disconnect and reconnect specific Multiple Cascade Links using 
the RealPresence Collaboration Server (RMX) Web Client / RealPresence Collaboration Server 
(RMX) Manager it not advisable to do so.
— If the main link is disconnected all sub-links are disconnected and deleted. 
Reconnecting the main link reconnects all sub-links.










