sundance-communications.com/forum Forums TDM Business Telephone Systems NEC Telephones & Systems Need to solve mystery....

Does the phone system have any SIP trunks? If it does, my post might be helpful.

We have the similar issues when we test the SIP lines on our demo system, it calls some random number like 111, 132, it also calls oversea numbers.

We called our SIP carriers, they said it is caused by some internet direct calls on SIP lines.
As our SIP port is open to Internet, hackers could call directly to the SIP port and make some calls through the phone system.

So we change the port forwarding polices, only connections from our SIP providers are passed through to our phone system.
it works.

Sound advice from Telephoneguy. Do what he says at the very least!

There used to be a feature called DISA that allowed things like that.

I hope you have this resolved by now but here's a couple other ideas. I've had this problem also but when I turn on "Trunk access code required" in 21-01-12 that usually fixes it. You could also turn on the 911 alarm. Specify which exts should receive the 911 alarm and it will show in the display what ext called it.