[asterisk-users] Pre-pending certain digits (like 9) to an outbound call number

[Joshua Kinard]

Hey all,

Working slowly on getting the myriad number of parts to my fax system plan together, and one of the pieces I want to nail is how to go about, for the outbound context (fax-out) pre-pending a digit onto a number?  I.e., for all my testing right now, I've been dialing '91XXXXXXXXXX', as the asterisk server doing faxing junctions into my old Rolm CBX switch, and so I need the '9' digit to dial outside numbers.  However, for deployment, I'd like to save the users confusion and have the server automatically append that leading '9' digit.

That possible by chance?  I assume it is, but off the top of my head, it didn't seem intuitive.  Below is the exten lines for my [fax-out] context, followed by some test exten lines that wound up failing:

exten => _X.,1,Dial(Zap/g1/${EXTEN}|20)
exten => _X.,n,Busy
exten => _X.,n,Hangup

; Test appending 9?
;;exten => _9XNPANXXXXXX,1,Dial(Zap/g1/${EXTEN}|20)
;;exten => _9XNPANXXXXXX,n,Busy
;;exten => _9XNPANXXXXXX,n,Hangup


I was trying to do some basic matching to the NANP formula to catch when someone accidentally mistypes a number, but that didn't match up and asterisk was complaining that no exten lines in the [fax-out] context were matching.

Also, is it possible offhand to block the dialing of certain numbers in the same context?  I.e., just as a check, to block faxes to 900 numbers?  I believe my Rolm CBX will do this for me, as it's got a pretty extensive list of area codes and exchanges that are known to be sinister in nature pre-loaded (probably needs updating, though...), but I figured that if I could block it in asterisk, to do so.  Save the Rolm a wee bit of processing and all (it is old, and probably senile...)

That, and I'd like to filter accidental '9911...' dials using this technique (which would dial 911 emergency, and that wouldn't be good, since I doubt faxes are a good method of calling in an emergency (unless they have a color fax and can discern that the red ink really isn't red ink...)).

Thoughts anyone?  Thanks!,

--Josh