3CX 15.5Sp5 and Exchange 2013 Error 403 when recording mailbox greeting

[roland.heimgartner]

We discovered now, that we are unable to record a new mailbox greeting with exchange 2013 and 3cx 15.5 Sp5
When analyzing the traffic with Wireshark we discovered a 403 forbidden error, with the message "Caller is not identified".
As the whole setup was running for years, we expect this to be a bug in this 3CX release.
and yes, the servername in 3CX is identical to the exchange servername in the sip invite.

Any idea how to solve this ?

 

[rheimgartner]

We discovered now, that we are unable to record a new mailbox greeting with exchange 2013 and 3cx 15.5 Sp5
When analyzing the traffic with Wireshark we discovered a 403 forbidden error, with the message "Caller is not identified".
As the whole setup was running for years, we expect this to be a bug in this 3CX release.
and yes, the servername in 3CX is identical to the exchange servername in the sip invite.

Any idea how to solve this ?[/QUOTE

Issue was due to 3cx was talking with Exchange using the external IP Address. a Firewall change solved the issue.