[Asterisk-Users] Zaptel - delay before dialing last DTMF digit?

[Kevin Walsh]

Richard Scobie [r.scobie at clear.net.nz] wrote:
> William R Sowerbutts wrote:
> > I have a TDM22B (TDM400 PCI + 2xFXO + 2xFXS). One FXO is connected to
> > the PSTN. 
> > 
> > When Asterisk places a call, it dials using DTMF. If I listen in on the
> > line during the dialing, there is a roughly one second pause between the
> > penultimate and the final digit -- proportionally much longer than the
> > pause between the preceeding digits. This accounts for about 25% of the
> > time taken to dial. 
> > 
> > Anyone know why this happens? I'd like to remove it.
> > 
> As I understand it, the echotraining pulse is sent during during this
> pause, so removing echotraining from your conf. should fix it.
> 
I was looking into this some time ago, while working out how to get
numbers to dial faster.  I was able to send the DTMF tones faster
but, as the delay before the last digit is related to the echo
training, I decided that it was best to leave the delay in place.

Sending the other digits faster makes up for the pause to a certain
degree.  To do this, edit the Zaptel driver's "digits.h" file and
change this line:

    #define DEFAULT_DTMF_LENGTH     100 * 5

The default is 100 * 8.  3 works for me too, but 2 is too quick.  I
thought it best to set it to 5, to allow some sort of a safety margin.
Your acceptable timing may vary, so you should experiment with it.
Find the lowest acceptable value and add 2 or 3.

Don't be tempted to mess with the PAUSE_LENGTH value, used by the 'w'
dial character.  The 'w' is used by the last digit pause mechanism and
will therefore affect the echo training.

-- 
   _/   _/  _/_/_/_/  _/    _/  _/_/_/  _/    _/
  _/_/_/   _/_/      _/    _/    _/    _/_/  _/   K e v i n   W a l s h
 _/ _/    _/          _/ _/     _/    _/  _/_/    kevin at cursor.biz
_/   _/  _/_/_/_/      _/    _/_/_/  _/    _/