When we run the firewall check (that does not lie...), we always get the following result:
resolving 'stun2.3cx.com'... done
resolving 'stun3.3cx.com'... done
resolving 'sip-alg-detector.3cx.com'... done
testing 3CX PhoneSystem 01 SIP Server... failed(How to resolve?)
stopping service... done
detecting SIP ALG... failed (How to resolve?)
testing port 5060... done
The reason for "detecting SIP ALG... failed" message is that we are behind an "AT&T Private Security Could" (fully managed by AT&T, which we have no ability to alter for obvious security reasons) and sip-alg-detector.3cx.com host is resolving to 34.141.156.185 > Groningen, Groningen, The Netherlands (NL), Europe, and we cannot communicate to that IP address - it there an alternative US based server that can be used instead of the one located in NL? (...or are we just the "lucky people" that will always have see the "failed" message?)
