Voicemails from Unified Messaging are showing the extension of the IP Gateway when a call is placed from an external number

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When I call one of my extensions on my PBX from an external number and leave a voicemail via Exchange UM, the email I get always shows it is from the extension associated with the IP Gateway which is 370. So the subject line always looks like this:

Voice Mail from 370

If the caller is internal, it shows up as the correct extension and if that extension is associated with a user in Exchange, it shows the name of the person it is associated to. So the subject line looks like this:

Voice Mail from Tim Broadaway

Anyone have any ideas on why my external callers are not getting their number passed to the Exchange server?

I'm running Exchange 2010 SP1 with the rollup 1 package installed. I am using an Audiocodes MP-114 FXO box for my IP Gateway. My PBX is a NEC DS2000.


Kevin Ca


I checked with our UM team and here is the feedback received:

What I can surmise from reading your question is that the PBX is sending the 370 as the caller information rather than sending the actual phone number that is calling into UM. The PBX would need to be configured to send the proper phone number of the actual caller rather than just stamping everything with the 370 identification of the PBX.

A network monitor capture would confirm this information. Run a network capture on the UM side and see how the call comes in from the gateway. It sounds like the From: is showing "370" only and nothing else. That would need to be sent differently in order for UM to do anything else with it. UM is only showing what it is getting from the gateway.

In the capture look at the SIP traffic for the INVITE. You can see the caller and the called party there. The From is the called party and this is what UM puts in the notification to the user.

Hope this helps!
Kevin Ca

Kevin Ca
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