[Asterisk-Users] Cell Phones and Tone Recognition

[Steve Underwood]

Hi Brian,

DTMF from a cell phone is rather different from DTMF from a land line, 
but not in any way that usually makes a difference. The cell phone 
codecs cannot carry DTMF properly, so the phone tells the base station, 
by a message, that a particular key is being pressed. The base station 
then sends the DTMF tones. The timing of the tones is totally divorced 
from what you actually press on the cell phone. This badly affects input 
methods based on the timing of the DTMF, but for most purposes it 
doesn't make a lot of difference.

Regards,
Steve


Brian wrote:

>When I dial from a cell phone into asterisk,
>I can press 1, 2, 3 etc to get to the various voicemail boxes and
>menus.. that's fine.
>but when I try 9-1-NXX-NXX-NXXX, i get
>  -- Hungup 'Zap/2-1'
>
>When I try the same thing from land line, everything works perfect.
>BTW (setup is 2 X100P cards)
>
>Is there any difference between the Cell phone and Land line that would
>make asterisk perform differently?
>  
>