I need some advice for Toll Fraud Prevention over PRI. We have an Asterisk PBX connecting over a PRI on a TA908. The customer is a repeat Toll Fraud Victim, their PBX spans several offices over a large geographic area and multiple Area Codes. To make things more difficult, as a part of our customer's day to day business they place outbound calls to many international countries and occasionally their outbound calls do not have caller ID on direct dial, forwarded or transferred calls. Suggestions?
Difficult to answer without more specifics. How is the toll fraud occurring? Rogue SIP phones registering? Call-forward to international destinations? Adtran IAD login compromised? (Did you delete the default user?) Some other vector?
Well this is pure speculation, because the customer is not sure how it is occurring... i believe it is a registered endpoint or a soft client. My only connection to them is the PRI handoff and i am really trying to find a way to lock that portion down by restricting the DNs that are able to place outbound calls. My only fear is that they will send me an extension or come in anonymous instead of 10 digit DN and their calls will fail and frustration factor increases...
remove "accept $ cost 0" on the PRI voice grouped trunk, and restricting accept to the specific list of DNs built in my switch and the lists from their remote offices.
Randy, you can use SABR (Source and ANI Based Routing) to restrict who is able to use a certain trunk based on a caller-ID pattern. The documentation is located here:
Thanks Jay... i will try this when i can get a list of TNs from the subscriber. But I thin I am still in trouble when they send me anonymous on legitimate calls.
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