[Asterisk-Users] Dial with no phone line connected

[Warren Burstein]

I have more FXO ports on TDM400's than I have PSTN lines available for
testing.  When all the lines were used up (the FXO ports are all in zap
group 2), and I did a Dial(Zap/G2/${phone},5) it thinks the Dial succeeded
even though there is neither line voltage nor dial tone.  Can at least the
lack of voltage be detected?  It would be good in case one of the phone
wires fell out that it would just move on to the next outgoing line.