asterisk DAHDI answer the call in ringing state
 

i have a problem in the FXO card
the call go to the answered state once it transferred to the provider so the a2billing detects it as a call and decreases the balance.

how can i configure DAHDI to go to answered mode after the callee answers the call (not in the ringing period) ?

i tried to set nsweronpolarityswitch=yes
but it makes the a2biiling not recording the call in the CDR although the call already answered.

plz help