[SnAzBaZ]

I would like to set one of our DDI's up so it forwards to an external PSTN number, but if that PSTN sends back a "busy" signal, the call is dropped into voicemail for a specific extension.

I don't see how this can be configured in 3CX V9?

Is it possible?

Thanks

[leejor]

When sending a call out on a PSTN line through a gateway, there is no way, other than audio (you listening) to know that a line is busy. The best you could hope for is a gateway that detects, and a provider that sends, a current reversal when the called party answers. This is not always available, so most gateways will "tell" 3CX that the called party has answered immediately after receiving the dialled digits.

[SnAzBaZ]

OK thanks. We use a gateway that can detect if the line is busy or not, and I see 3CX say "busy" in the log file, just a shame we can't turn that notification into something more useful.

[leejor]

If your gateway is actually capable of detecting an audio busy signal, and then sending a SIP message to that effect, then it may be possible. It all depends on whether or not 3CX is capable of doing anything with that message, and of that, I'm not sure.