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How to track down who is making expensive international calls

Level 1
Level 1

CUCM System version:



We received our AT&T bill and there's $2,400 international off-net charge.  I'm trying to figure out who made the call.  The number listed on the bill is 775-900-0000, which has a Nevada area code, we are in the United states, so it doesn't seem like that should be an international call (but that's not the issue at hand right now).


I thought it would be as simple as searching CDR for the phone number.  But, I've searched a year's time span for the number and there is no record of it ever being dialed. Also, the bill doesn't give handy info like exactly when the call was made.


Does anyone have any idea how I can track this call down in CUCM?



1 Reply 1

It may be that the toll-fraud was on the router end rather than the CUCM end. What type of circuit do you have to your PSTN provider?

Take a look at the following document. It refers to CUCME, but it's really about protecting your edge router. The applicable prevention steps (ip address trust list, direct-inward-dial on ISDN, etc.) should be configured on your PSTN-facing gear:

CUCME Administrator Guide - Chapter: Toll-Fraud Prevention

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