I have a tda 30 which has PSTN trunks running thru a Msg 2 card. When you hang up, the system holds the line and does not release until the customer picks up.

1.Does the system support busy tone detection?
if it does do we need additional boards and what are are the programming blocks

2.Line reversal has been withdrawn in Australia
(ROI)so is not an option.
3.CPC on pstn lines is it an option or standard on
Telstra lines in Australia.

Thanks in advance.