[Asterisk-Users] Subject: Re: Dial with no phone line connected

[Rich Adamson]

> >> 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.
> 
> > Yes, the chip set on the TDM card does provide flags for indicating no
> > voltage (disconnected), low voltage (something is off hook), and normal
> > pstn voltage (on-hook).
> 
> > About three months ago, Mark added code that detected when a pstn line was
> > unavailable (eg, rj11 disconnected, damaged cable, someone disconnected
> > the wrong pstn line). The code created a problem for someone (I don't
> > remember the details), and he changed the code to be a compile-time config
> > option.
> 
> > I don't have any past references to that other then from memory. Maybe
> > someone that can read code can find that option for you.
> 
> I read code, so I looked for this code in the sources, I remembered that
> "fxstest stats" prints the voltage, found that it did an ioctl
> WCFXS_GET_STATS, and searched for this in both asterisk and zaptel (version
> 1.0.0) of each, and found the only place that this constant appears is in
> fxstest and the wcfxs driver.  Is there a different way to test for a
> disconnected cable other than this ioctl?

Not to the best of my knowledge.
 
> Could it have been taken out entirely and not just ifdef'd out?

Yes it could have been.

How old of code are you looking at? The wcfxs driver was renamed to wctdm
some time ago. Current cvs doesn't include it.