axt2400 – disconnect problem

hi, all,

i have problem on my quintum axt2400. box is configured to receive calls from ip side and pass thru pstn. the problem is with call duration. it is not accurate. out of 10 connected calls, about 2 will have 0 duration. it is set for loopstart-reverse battery, answer/disconnect supervision. any help will be greatly appreciated.

tks a lot!