h323 gateway doing strange calls

[Antonio Brandao]

Hi All,

I have a E1 link configured on my cisco router, this gateway is connected to my Cisco Call Manager.

las month the carrier company send a bill with a lot of international call for strange countries like romenia and singapore.

I runned the debug on gateway and I can see the call going from the gateway for PSTN but I can not see it on CDR files on Call Manager.

The gateway is doing a h323 trunk with the call manager.

So what can be that ? some virus ? some call relay feature open ? or what ?

AB

[Christopher Graham]

Assuming this is a PRI, make sure you have 'direct-inward-dial' configured under the inbound POTS dial peers.  This will prevent the circuit from providing secondary dial tone, and allowing outbound calls to be made.

[maharris · Accepted solution]

You probably want to take a look at this Toll Fraud Prevention tech note - it is for CME, but would apply to any H323 or sip gateway that is reachable on the internet:

http://www.cisco.com/en/US/products/sw/voicesw/ps4625/products_tech_note09186a00809dc487.shtml#h323

The routers will accept sip and h323 requests by default, and you have to disable that.  It changes in 15.1(2)T, and you need to be aware

of that too, or your good traffic won't work!:

http://www.cisco.com/en/US/tech/tk652/tk90/technologies_tech_note09186a0080b3e123.shtml

Mary Beth

[Antonio Brandao]

Hi Maharis,

Thats was very helpful, thank you so much.

AB