Thanks for taking intrest qwerty12!

Perhaps if I explain the purpose of my request things might become more clear.
I'm making a python script, which works on creating a missed call for the other party.
That is, it dials a number, waits for a "valid" dial tone to beep for say 2 seconds, then hangs up.

I got all the mechanics of creating the call and hanging it up and running.
The only problem is, how to distinguish between dialtones (Busy, No Service, etc...)?

Thanks again!