Hi,
I am facing a very annoying issue with asterisk CDR log.
All DAHDI outgoing calls showing as “ANSWERED” and “bill seconds” greater than zero even though the calls were not answered or busy line.
I am using Sangoma (Wanpipe) for connecting with landlines PBX Company.
SIP and Gtalk calls are working fine.
Any idea what causes this issue?
You probably need to address this to Sangoma.
On PCI analogue cards, this happens if you do not have answer supervision. Answer supervision requires support from the PSTN operator and enabling in Asterisk. I think the only analogue answer supervision protocol that chan_dahdi supports is line reversal. If you enable this and the PSTN operator doesn’t use it, calls will appear never to be answered.
If this is ISDN, you should get answer supervision at the right time. If you don’t, it will be a network operator issue.
Thank you for this information.
It seems no simple solution. 
I know this a known problem for many countries that do not support reverse polarity signal switch at pick-up and hang-up point.
I also understand that there is “Remote Party Answer Supervision” software that analyses the human voice to determine the approximate bill seconds.
Any idea about that software?
try to enable reverse polarity with both sides.
Unfortunately, I have no control on the other side. 