Polycom RealPresence Collaboration Server (RMX) 1500/2000/4000 Administrator’s Guide
19-28 Polycom, Inc.
Figure 20 Call Flow from ISDN Endpoint to Polycom DMA with Automatically
Generated Forwarded Dial String
Example:
Figure 1 shows the call flow assuming the following parameters:
First Dial-in Number 5705550
Last Dial-in Number 5705560
Use Dial-in Numbers as Destination ID Selected
PSTN participant dials (212)5705555
Destination Prefix (DMA Gatekeeper) 26
Number of Rightmost Digits to Append 4
DMA Meeting Room ID 5555

PSTN Dial-in Using GK Prefix

When connecting to an RMX that is standalone or part of a DMA solution deployment,
PSTN participants are prompted by an IVR message requesting the Destination Conference ID
followed by the # key to be entered using the DTMF input keypad.
Including the Gatekeeper Prefix in the DTMF input string enables PSTN participants to use
the input string when connecting to an RMX whether the RMX is a standalone MCU or part
of a DMA solution deployment.
Enabling PSTN dial-in using GK prefix
The feature is enabled by the USE_GK_PREFIX_FOR_PSTN_CALLS System Flag in
system.cfg. For more information see "Modifying System Flags” on page 22-1.