Chapter 5-Cascading Conferences
Polycom, Inc. 5-3
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 RMX and an MGC that is functioning as
a Gateway, if the participant layouts on the MGC 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.
Guidelines
This option is supported with:
—With MPM+ and MPMx cards.
—In H.323, SIP and ISDN environments.
—For 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” on page 22-1.

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 RMX 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.