two calls mixed together

[Randika]

Hi

We have 3cx version 12.5 with grandstraem phones (around 300).

Sometimes users have complained (although its very rare) that they can hear other peoples conversations. So I have investigated one instance of this and I found two internal calls have mixed together ( I have the call recordings which clearly hear the cross talk)
I assume this is nothing to do with our VoIP provider because the two calls were totally between internal extensions.

Those two calls were started in the same minute (only 6 Seconds difference) and they are not in the same call group (call queue)

I have the server activity log for the above two calls

15-Apr-2015 13:56:29:.899 [CM503001] call (c:4583) incoming call from Extn:353 to <sip:[email protected]:5060>
15-Apr-2015 13:56:36:.737 [CM503001] call (c:4584) incoming call from Extn:334 to <sip:[email protected]:5060>

Does anybody know how this can happen ?

Thanks

 

[Allen_Miller]

You might want to set up Wireshark to capture traffic the next time this happens to better diagnose what is going on.

Allen

 

[eagle2]

You can easily run into such scenario, if some of your extensions are behind NAT router (e.g. in another office) and this router is not doing NAT or PAT correctly (most cheap home style routers are not behaving properly). Use Wireshark to identify the problem (as Allen recommends above).