Asterisk who is calling every minute?

Question

I know the basics of Asterisk . When I go into the console by running the command asterisk -rvvv I see the following:

If you notice I first get a notice:

[Aug 24 19:14:43] NOTICE[5097][C-00000036]: chan_sip.c:25877 handle_request_invite: Call from '' (62.210.26.82:5079) to extension '011972599166454' rejected because extension not found in context 'default'.

and then I get a warning and this happens every minute.

So my question is who is dailing extension 011972599166454 ? If I add:

[default]   
exten => _X.66454,1,NoOp(Hanging up call)
same  => n, Hangup

to my extensions.conf file this solves the problem. But why is someone making a call every minute? to open the NAT? Should I stop this?

Answer 1

I'd just ban the IP address with your firewall and forget it.

If you are curious, you can set sip set debug ip <ip> and check SIP headers, maybe you could find some info about callee in the headers.
Also you can trace the IP with whois and try to find admins' contact to discuss the issue.

Answer 2

This is scanning bot looking for free calls. Just disable guest calling sip.conf: allowguest=no . Then any not authenticated connections will be ignored. It will help with new IPs also.

http://www.voip-info.org/wiki/view/Asterisk+sip+allowguest

Answer 3

看来这是一种黑客尝试。...使用Fail2Ban阻止任何可疑的呼叫尝试。