[Asterisk-Users] Distinguish between voice and data call

[Mickey Binder]

Hi

I have an Asterisk installation with some SIP and MGPC devices, and I also have a TE410P on a E1 line. 
If I make an outside ISDN data call to asterisk the phone rings as usual and if I answer it, I just hear some clicks. 

I've read that the D-Channel has information about the call, if its voice or data. 
Is it somehow possible to end/ignore this call already before it is ringing?

regards
Mickey Binder