DTMF detection from cell phones

I have configured my asterisk box so that I can dial in from my cellphone, press a key and an agi script fires off. The script retrieves a current weather radar and sends it as a txt message to my cell phone. (Yes, this is cooler than just accessing the Internet from my cellphone!)

However, asterisk seems to have problems detecting keypresses from cellphones. If I press the key on the cellphone during the ring sound asterisk doesn’t recognize the keypress. If I press it between rings, then it works fine.

The incoming calls come in to a TDM410P DAHDI analog line. Anyone know of any way to fix this?


Don’t generate a ringing sound. I believe on only the musical style dialtone is designed not to conflict with DTMF (the old purring dialtone doe).