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New Member

No Caller ID on PSTN

My PSTN's are showing "Unknown Caller" when I try to call out on them. They would like it to show the Caller ID assigned to the line. Any ideas? CM 4.0.....

New Member

Re: No Caller ID on PSTN

Are these analog lines or digital lines? If they are analog Loopstart or GroundStart it has been my experience that they will send out whatever number is assigned to them by the carrier regardless of what you configure on the route patterns or the external caller ID Mask. If they are digital lines then you have a couple of things to check. You can either set an external Caller ID Mask on the route pattern that sends the same number for every outgoing call, for instance 222-333-4444 or if your DID's map to say the last 4 digits of the phone extensions, you could use 222-333-XXXX and allow the last 4 digits to come from the phone. I have found the most flexable way is to check the Use Calling Party's External Phone Number Mask under the Calling Party Transformations section and putting nothing in the route pattern, then putting the entire number in the External Caller ID mask on the line configuration of the phone. I set this up durring the initial configuration of the phones using the BAT tool, so if you already have a lot of phones configured making the change by hand can be very time consuming.

If however you are saying that incoming calls to your system from analog PSTN lines are showing unknown caller, then the problem could be your gateway configuration. CallerID on Analog PSTN lines is not supported if your gateway is MGCP.

New Member

Re: No Caller ID on PSTN

Thanks for the reply Chris. These are analog PSTN lines and it's setup as MGCP. Which looks like that's my problem. What kind of digital line do I need from the Telco?