Chapter 5-Cascading Conferences
Polycom, Inc. 5-13

Suppression of DTMF Forwarding

Forwarding of the DTMF codes from one conference to another over an ISDN cascading link
is not automatically suppressed as with IP cascading link and it can be limited to basic
operations while suppressing all other operations by a system flag:
DTMF_FORWARD_ANY_DIGIT_TIMER_SECONDS.
System Flag Settings
The DTMF_FORWARD_ANY_DIGIT_TIMER_SECONDS flag determines the time
period (in seconds) that MCU A will forward DTMF inputs from conference A participants
to MCU B.
Once the timer expires, most of the DTMF codes (excluding five operations as for IP links)
entered in conference A will not be forwarded to conference B. This is done to prevent an
operation requested by a participant individually (for example, mute my line) to be applied
to all the participants in conference B.
Flag range (in seconds): 0 - 360000
This flag is defined on MCU A (the calling MCU).
If a flag is not listed in the System Flags list it must be added to the system.cfg file before it can
be modified. For more details on defining system flags, see "Modifying System Flags” on
page 22-1.
•On the Codian gateway Content is not supported with line rates of 128Kbps and below.
•When using the following topology:
H.323 endpoint ->Codian Gateway -> ISDN Link -> RMX -> H.323 endpoint, the Codian
Gateway is unable to send DTMF and the call is disconnected (VNGFE- 3587).
•Sending Content from a participant over Radvision Gateway to a conference/participant, the
GWP20 patch must be installed in the RadVision gateway:
On the Radvision gateway, open the GWP20 User Interface. Click Settings/Advanced
Commands. In the Command box enter H239OlcPatch. In the Parameters box enter Enable
and then click Send.