[asterisk-users] Defining what an extension should do after the Dial() command returns busy.

[Ernie Dunbar]

We have a customer who wants to forward an extension to their cell phone,
if and only if that extension is "unavailable", or when the Dial() command
times out. However, should the Dial() command return "busy" it should go
to voicemail instead.

As far as I know, the dialplan doesn't support this. Certainly not
natively or in any particularly easy or obvious way, and I can't find
anything on voip-info.org to suggest that there is.