RealPresence Collaboration Server (RMX) 1500/1800/2000/4000 Administrator’s Guide
Polycom®, Inc. 241

Flags Controlling Cascading Layouts

Setting the FORCE_1X1_LAYOUT_ON_CASCADED_LINK_CONNECTION System Flag to YES
(default) automatically forces the cascading link to Full Screen (1x1) in CP conferences, hence
displaying the speaker of one conference to a full window in the video layout of the other conference.
Set this flag to NO when cascading between an Collaboration Server and an MCU that is functioning
as a Gateway, if the participant layouts on the MCU are not to be forced to 1X1.
Setting the AVOID_VIDEO_LOOP_BACK_IN_CASCADE System Flag to YES (default) prevents
the speaker’s image from being sent back through the participant link from the cascaded conference.
This can occur in cascaded conferences with conference layouts other than 1x1. It results in the
speaker’s own video image being displayed in the speaker’s video layout.
This option is supported with:
In IP (H.323, SIP) and ISDN environments.
Basic Cascading of Continuous Presence and Video Switched conferences. If a Master MCU has
two slave MCUs, participants connected to the slave MCUs will not receive video from each other.
Video resolution will be according to the Resolution Configuration, or VSW profile.
For more details on defining system flags, see Modifying System Flags.
DTMF Forwarding
When two conferences are connected over an IP link, DTMF codes from one conference are not forwarded
to the second conference with the exception of the following operations that are available throughout the
conference and the forwarding of their DTMF codes is not suppressed (i.e. they will apply to both
conferences):
Terminate conference.
Mute all but me.
Unmute all but me.
Secure conference.
Unsecure conference.
Play Tone Upon Cascading Link Connection
The Collaboration Server can be configured to play a tone when a cascading link between conferences is
established. The tone is played in both conferences.
This tone is not played when the cascading link disconnects from the conferences.
The tone used to notify that the cascading link connection has been established cannot be customized.
The option to play a tone when the cascading link is established is enabled by setting the System Flag
CASCADE_LINK_PLAY_TONE_ON_CONNECTION to YES.
Default value: NO.
The tone volume is controlled by the same flag as the IVR messages and tones:
IVR_MESSAGE_VOLUME.
During cascading between a gateway and a conference all DTMF codes are forwarded from the
gateway to the conference and vice versa.