For an inbound route that has fax detect enabled, if a regular voice call comes in that goes to an automated attendant, it is picked up and then there is a long delay (equal to or greater than the configured fax detect time) before the automated attendant outbound announcement plays.
This can be a little annoying to callers, and the more impatient among them might think something is wrong and hang up (and maybe call again, maybe not).
It also makes it impossible to implement an automated attendant outgoing message that says something like "If you would like to send a fax, start it now. Otherwise, press 1 for John, 2 for Jane, 3 for Fred, or 0 for the receptionist.".
It would be better if Asterisk would detect a fax tone WHILE it is playing the outgoing message and not only BEFORE it starts playing the outgoing message.
I know this is possible, because fax+answering machines have worked that way for a decade or more.
The people intimately involved with Asterisk development... and with selling stuff for Asterisk... including the folks that wrote the Asterisk Definitive Guide, like to claim that there is virtually nothing that Asterisk can't do. So, this is something I would like Asterisk to do. Anyone have any idea how I would go about programming it to detect faxes while playing the OGM?