[VoIP] Asterisk DTMF Reality Check

[John Novack]

Greg Blakely wrote:
> But that really quick burst of DTMF isn't enough for most auto
> attendants, and sometimes isn't enough for my Qwest POTS line.
>  
> John, I just saw a post you'd made to the Asterisk Users mailing list about having to change the duration of DTMF tones in the source directories, and then re-compiling.  I'm wondering if you (or any of you, really) could tell me WHAT parameter(s) needs to be changed in WHAT config file.
Not sure which John you mean, but this sort of problem has existed for 
years, due to software engineers not having either an interest in 
history or reading specifications
I remember in the mid 80's installing an early electronic system that 
had as its default a 55 ms DTMF burst, when standards at that time 
called for 75-80 Ms duration
Any AA or answering machine remote SHOULD work with 80 Ms duration, PSTN 
CO's seem to work with 55 Ms even.
Perhaps John C or Russ P can figure out where this occurs, and where to 
make the change.

It would also be nice if the longer figure became the default in future 
distributions, along with the change that needs to be made for pulse 
dialing, which has been known for a long time, but the powers that be 
don't seem to care or can't be bothered.


John Novack