OpenVox A400E >>> Detecting phone is answered?!

1. you need oen the reverse polarity signal to detect otherside answer of hangup.
after you open reverse polarity signal from the provider. edit the /etc/asterisk/chan_dahdi.conf
answeronpolarityswitch=yes
hanguponpolarityswitch=yes
and command the busydetect and busycount parameter.

That has been set already. As mentioned this is the same config as the previous system where it was working ok:

answeronpolarityswitch=yes
hanguponpolarityswitch=yes
rxgain=-0.0
txgain=0.0
callprogress=yes
callwaiting=no
transfer=yes
canpark=yes
cancallforward=yes
callreturn=no
echocancel=yes
echocancelwhenbridged=no
immediate=no
useincomingcalleridondahditransfer=yes
loadzone=uk
defaultzone=uk
usecallerid=yes
ukcallerid=yes
cidsignalling=v23 ; Added for UK CLI detection
cidstart=polarity ; Added for UK CLI detection
sendcalleridafter=0
callerid=asreceived ; propagate the CID received from BT.
busydetect=yes
busycount=3
faxdetect=no
progzone=uk
signalling=fxs_ks

1. if you have reverse polarity signal for answer and hangup, you should command busydetect and busycount parameter.
2. you mean same pstn line before work well on same card but recently can't detect remote answer signal?
3. you can add my skype:dario.hu2 and prepare teamvidw for check.