RealPresence Collaboration Server (RMX) 1500/1800/2000/4000 Administrator’s Guide
Polycom®, Inc. 614
ISDN Participants
Two dialing methods are available to ISDN/PSTN participants:
●Dialing via Gateway IVR for ISDN Participants
●Direct Dial-in to Endpoints or DMA VMR using Automatically Generated Destination Numbers.
This dialing method is available from Version 7.1.
In addition, PSTN participants can dial the Gateway IVR and can use the MCU or DMA prefix in the
gatekeeper together with the conference ID/endpoint alias as the destination string to simplify the input. This
is one of the methods for PSTN participants to connect to a virtual Meeting Room on the DMA.

Dialing via Gateway IVR for ISDN Participants

In this flow, the calling endpoint enters the dialing string that includes the access number to the
Collaboration Server Gateway Profile.
The endpoint connects to the Collaboration Server and is welcomed by the IVR Welcome slide and
message: Please enter the destination number followed by the dial tone.
Using the endpoint’s DTMF input device such as remote control, the participant enters the number of the
destination endpoint followed by the # key. Only one number can be dialed.
While the system dials to the destination endpoints, the participant hears the dialing rings. During the
connection phase, the number being dialed is displayed on the screen of the calling endpoint.
If the call is not answered or it cannot be completed using one communication protocol, the system will try
to connect the endpoint using the next communication protocol according to the selected protocols in the
following order: H.323, SIP and ISDN.
PSTN numbers are identified separately and are dialed immediately without trying other connections.
If the endpoint is busy, the system will not try to connect the endpoint using another protocol.
If the call is not completed after trying all possible protocols, the system displays the number that was dialed
on the calling endpoint’s screen and the reason for not completing the call. For details, see Connection
Indications.
•DTMF tones and Caller-id are not passed end-to-end.
•In order to support RTV, the SIP Server Type must be defined as Microsoft.