After hours forward to external number issues

[jacobw19801]

I have a client running v20 on premise setup with grandstream ht841. They need after hours calls to go to a cell phone. I set the office hours, then set the ring group office closed route to call the cell number. If I call in, it forwards to the cell phone and the cell phone rings but when they pick up, nothing. On my end it is just ringing and ringing. Its like 3cx is forwarding fine, but not connecting the two calls to each other. I have tried this using ring group and ring queue with similar results, it will always call the external number but never connect the two. I have also tried for after hours, forwarding to a user, then setting forwarding there to an external number with the same results. No matter what I change, 3cx will not connect the two calls. Any ideas?

 

[leejor]

It may be a Codec, or possibly a port issue. If you have access to the 3CX Activity Log (Verbose), then that would be the place to start.

 

[VoIPTools]

My guess is that you are using an unsupported SIP trunk. This kind of thing should just work. If you can receive and make external calls through the same trunk, then it should work. If it does not work, then it is probably a SIP trunk misconfiguration or as @leejor suggested, perhaps a firewall issue. Does your firewall pass the firewall checker tests?