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New Member

analog device connected to FXO port, caller ID

I have Valcom door phones connected to a Valcom 2904 door controller. The Valcom controller is connected to my VoIP system via a FXO port on my 2921 router.

I'm using MGCP.

After configuring everything in the 2921 and in CUCM (, I can successfully press the button on the door phones and connect to the DN I want to. The only issue I have is on the called parties phone, the call comes in as an "unknown" caller. I cannot figure out how to assign a DN to the FXO port or have it send some sort of Caller ID so the called party knows the door phones are calling.

Any suggestions would be appreciated.



Re: analog device connected to FXO port, caller ID

Have you enabled caller ID on the endpoint config page? It's disabled by default.


New Member

analog device connected to FXO port, caller ID

I did try to enable caller ID. When it was enabled, the call would not connect between the analog device and my targeted DN.

I tried via CUCM as you show and also tried via programming in the 2921.

I did see various other posts that suggested there was a known issue with caller ID and MGCP, but my understanding was it dealt with incoming caller ID to the device connected to the FXO port. I want the device that connects to the FXO port to provide caller ID to it's called party.

I thought maybe checking "Transmit UTF-8 for calling party name" would work, but it didn't. What field would it transmit for calling party name anyway.....the device description field?

Thanks Gareth!


analog device connected to FXO port, caller ID


I had a quick look at the Valcom site, and it doesn't look like those door phones actually pass out a CallerID, just distinctive tones.

You might want to check with them before banging your head against the wall.

New Member

analog device connected to FXO port, caller ID


Too late.....already banging my head!!

Maybe I don't understand how the FXO port works.

I realize the Valcom devices don't send any CallerID. I was assuming there was a way I could program the FXO port to pass out a caller ID for anything that used the port to call out. If I were to hook a POTS phone to the FXO port, could I assign that phone an Extension number or DN in call manager or via the router config??

I have ATA187's and VG204's (FXS ports) that I can assign DN's to the analog devices I connect to. Is that because of the difference between FXS and FXO??


analog device connected to FXO port, caller ID

Chris... I feel your pain!

As far as I'm aware, an FXO can only receive CLID, not transmit but I'm not sure if there's a way around this or not.

I'm just wondering if there's anything on call manager that you can do. Are you using a route pattern for the dooor controller? Maybe a calling party transform mask?