Problem in cdr

Hi guys. I’ve problem with my cdr. I found that duration and billsecond in my cdr show the same time. I’m using ‘Auhenticate’ to verify the caller id. Previously I used DISA and the duration and billsecond are different. But it was very slow. So i changed to Authenticate but now the duration and bill second are same. Billsecond start counting whenever the PSTN get connected to gateway and start Athenticate. It suppost to start when it get connected to the destinataion. For your information my asterisk servers is connected to PRI. I couldn’t understand why i face this problem when i switched to Auheticate from DISA. Guys pls help me to solve this.