Dtmf/ touch tone disable per call?


…I ran into problems when I was trying to connect an alarm system to asterisk. It sends tones that asterisk detects and “plays” them to the callee. The issue is that pauses and tone length are different from those the alarm system sends.
Is there a way to avoid this behaviour? Something like “bypassing” the remodulation? The only solution I found yet would be to change the tone frequencies in asterisk that way that it doesn’t detect such tones at all but this is out of the question.
The alarm system is an analog device connected to the PBX using a digital/analog adapter and an ISDN-interface sold by junghanns (octobri). Asterisk is bristuffed (1.4.17)

Thanks in advance.