Problem with CDR


I’ve installed Elastix 2.4 with an analog card OpenVox with only one line configured. Incoming and outgoing calls are done ok.
But there is a problem regarding the behavior of the outgoing calls and the CDR. When the call is in process Elastix takes the ringback tone of the provider as an ANSWERED and generates a record in the CDR-report with that call and with answer time even if the call at the end wasn’t answered.
For instance if I call my cell phone the time as answered starts from the moment there is a ringback even if at the end I reject that call from the cell phone. So it add a new record with cost in the CDR but is not real because the call wasn’t answered and wasn’t a cost.
I suppose is something related to the dahdi configuration of the analog line but I don’t know what could be the right setting.

Could you advice me???
Many thanks.

Analog lines do not have call progress signalling.
They know:
On hook
Off hook

So all calls on FXO loop (kewl) are considered answered.

Thanks for the answer.
So there is not a message related with the answer status? maybe the off hook (of the called party).
I am really suprised that everybody with analog lines are having false CDR-reports because the system doesn’t undertand the answered message. At least that is not normal with analog lines per se, I am working with Avaya PBXs from 10 years ago and out CDR reports are ok, and the PBX doesn’t count the call until it is answered by the called.
Really surprised about it.

Avaya can’t know without being told. Is your carrier doing a polarity flip to indicate answer?

Thanks for the answer, I don’t know what is a polarity flip, but I am pretty sure the CDR in Avaya is aware of the event answer, and even Asterisk in the logs in able to know when the call is answered by the called party. So I don’t understand by can not use that answer message.