[Asterisk-Users] Line death not recognized on TDM400P?

[Rich Adamson]

> > > A customer of mine has 3 TDM400P cards in a box running asterisk. 
> > > On each card he has four FXO modules.  
> > > 
> > > I have set up the dialplan to dial via group 1 for an outgoing call.
> > > 
> > > Channels 1-12 are in group 1.
> > > 
> > > If he plugs a telephone cable into socket 2 or 3 etc, but not 1,
> > > when he dials out, it still tries to make the call via socket 1.
> > > 
> > > Straight away the console says that it has dialed the number via g1
> > > and that it is connecting sip/bla with zap/1-1 (or some such)...
> > > 
> > > On my X100P I get a red alarm if the phone cable is not plugged in. 
> > > Is there any way to do this with the TDM400P?
> > > 
> > > They would like to be able to unplug lines and use them for other
> > > purposes at times.
> > > 
> > > Make sense?
> > > 
> > > I kinda thought that asterisk would realise that nothing was 
> > > connected to the TDM card and try the second socket, the third
> > > etc...
> > 
> > It makes sense, but the code to detect unused rj11's is not in * now.
> > 
> > In fact, you'll find that unplugging and replugging the rj11's will
> > cause * to fail after a while. (At least that was the case about a
> > month ago and there really haven't been any changes to the fxo
> > software for some time.)
> > 
> > There are no alarms or other indicators available that would suggest a
> > port has failed or is unavailable.
> > 
> So basically if there is a problem with line 1 out of 12, no calls 
> are going to get through...surely this isn't expected behaviour.
> 
> Is there any way to fix this (I'm the New Zealand distributor of 
> Digium products and if this is the case, they will be returning to 
> their propreity pabx)?
> 
> Should I open a bugnote?
> 
> I spoke to a few people on IRC last night who confirmed that this is 
> the case.  It seems crazy.  If I send a fax using a fax machine it 
> works, if I dial a number with a modem it works (even a $5 modem) so 
> why can't it work in asterisk?  It used to work on the X100P's...
> 
> I just want the card not to dial if there is no dialtone...

The only response that seems to have any real logic in it is this...

- The TDM card seems to have the hardware facilities (eg, chipsets) on
  it to do substantially more then what it is today
- There are very few * developers that truly understand the low level
  pstn interface requirements necessary to code additional functionality
  into the TDM drivers
- Mark is one of the few that can translate pstn interface requirements
  into real code, and his time seems to be distributed across a lot of
  different areas (not sure when he gets to sleep)
- the overall design of the TDM card relies on the host system processor 
  to interpret dtmf tones (from digital pcm data flows), etc. Therefore
  adding functionality to the drivers is a delicate balance between
  the function and burning host cycles that might be disruptive to 
  other * components
- detecting dial tone before dialing would seem to be trevial (I can
  easily say that as a non programmer), but someone needs to add the
  code to do it reliably
- the chip set in use already has provisions to detect CO battery, line
  off hook (presumably from a bridged analog phone), battery reversal
  (supervision), etc, but someone needs to add the code to use it.

Best guess is time constraints are having "the" biggest impact. The 
unwritten default condition for * development is that if a feature or
bug fix is expected/required, there is a high probability it won't be
addressed unless a bug report is generated, or, one of the developers
has the same problem; sort of the squeaky wheel gets the grease.

It's my belief (right, wrong or indifferent) that digium is missing
out on a major revenue stream due to a lack of understanding "marketing"
and the prioritization of certain development functions (like the 
above) required to sustain/grow sales. If digium is going to rely on
the sales of these cards to grow/support *, then something is going
to have to change since user experience/opinion for those products
is heading in a downward direction (not upward).

I'm certainly not ragging on anyone, just stating an opinion FWIW.

Rich