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UC320 with AT&T Analog Lines - BRI Trunk Needed

Michael Russo

Good afternoon fellas..

Here is the situation I am in, now feel free to correct me if I'm wrong.

I have a UC320 with SPA504G Phones.  I have AT&T Analog Phone lines (7 to be exact).  The last 4 of the numbers are 968X (1,2,3,4,5,6,7).

We need all outgoing numbers to show up as 9686.  Is this possible?  I think I may need added hardware, if so what?  I looked at the Mediatrix 4401, but not sure if this is what I need.   On top of hardware, is this an extra monthly service I need?

Thanks for your time, and I appreciate ANY input!

6 Replies 6



If you need to connect BRI - ISDN lines, yes you would need a Mediatrix gateway to connect BRI line. UC320 is connected to the Mediatrix using a SIP trunk and caller ID can be controlled on SIP trunk.

The Mediatrix 4401 is a one time cost. However there may be support costs associated with it. It is similar to getting a SPA8800.

Which country  is this going to deployed in? I did not know AT&T had BRI lines.


United States:  What exactly is a BRI line?  Maybe they don't support them?  Am I screwed?

I called AT&T and they were extremely helpful! (sarcasm)

They told me that AT&T No longer supports BRI, and they then said what you want to achieve is possible, but you need to deal with a phone system that supports it... Ugh!


BRI is an ISDN standard that is currently popular is Europe and Australia. I have not heard of anyone using BRI in the US. You are likely talking about FXO lines / Analog line .  To answer your original question, 4 FXO/Analog lines can be connected to the UC320. A SPA 8800 will give you ability to add 4 additional FXO lines.

Caller ID on the FXO cannot be controlled by the UC320. It is completely controlled by the Telco. You would need to call AT&T back for that. I had to call them yesterday for my DSL at home, it was no fun. If you would like to control each individual line and have it mapped to a button you would need to operate the UC320 in Key System mode.

Look for  Deploying the UC300 solution as a Key System (partner only)


Christopher Edgeworth
Frequent Contributor
Frequent Contributor

Hi Michael,

For FXO lines, AT&T needs to provision all of the numbers in the group to have the same outbound calling party number (9686).  Calling ID is not send from FXO endpoints, it is provisioned by your FXO service provider.  Just like you don't provision your name and number on your home phone (an FXO), it is done at the central office by your provider.

Hope this helps.


Guys, I appreciate the input from both of you.  However, I call AT&T and they tell me what I want to achieve is only do-able with using my PBX system.. Should I ask them to talk with someone else?  I know there has to be a way to obtain this feature.. It's very needed!

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