Some legacy applications use the virtual COM port of the Dialogic® Diva® Media Board to process incoming calls. This is because driving the COM port and using the "AT" command set is familiar technology, and it is (at least to some degree) portable across different modems.
Some applications wish to pick up the caller's number (caller ID) so that this can be stored or used for security purposes or for database lookup. The Diva Media Board virtual COM port supports this.
For example, if one is trying to connect incoming V.110 calls (selected with AT&F3 on the Diva Media Board), one could do this:
(#CID=1 selects caller ID, S0=0 disables auto-answer)
An incoming call would then present the caller ID like this:
RING CID: 02089678000
After reading the CID, the application can pick up the incoming call using the command "ATA".
in some telco networks Caller ID is not provided free of charge, but instead is a subscribed service. Therefore, if this service is not enabled, the above commands will not work. You can check if the Caller ID is being seen by the Diva Media Board either by running a trace, or by looking at the Diva Monitor, which displays telephone numbers on connected calls if they are available.