asterisk users - Jan 2006 - SOLVED: Hung Zap channels connected to old key system

We've got a Toshiba DK system w/ analog ports that went to a  
voicemail server.  I swapped in an Asterisk box with a Digium 4-port  
fxo card.  It /almost/ worked perfectly.

The problem is that Zap channels never hang up.  They have to time out.

I set up MeetMe, but all Zap channels hung forever.  Very annoying.   
Same thing for FXO-to-FXO bridges.

I figured out today why and fixed it.  Some proprietary voicemail  
systems (and probably tie-lines, too) like to use DTMF tones instead  
of standard ground/loop/kewl whatever signaling.  Our key system was  
programmed to use such DTMF tones instead of the usual analog  
signaling on those ports. (I think it was program 31 on our Toshiba  
DK40i)  Asterisk of course ignored those, but the other systems used  
those for line signaling (including our previous 3rd party system).

Amusingly, I know now why for years we kept hearing loud DTMF tones  
when our branch office picked up their phones.  Their system, too,  
was configured to have those analog lines be connected to a voicemail  
system and not to a FXO port on a T1 CSU.


Phil

Philip Edelbrock wrote:
> 
> We've got a Toshiba DK system w/ analog ports that went to a  voicemail
> server.  I swapped in an Asterisk box with a Digium 4-port  fxo card.  
> It /almost/ worked perfectly.
> 
> The problem is that Zap channels never hang up.  They have to time out.
> 
> I set up MeetMe, but all Zap channels hung forever.  Very annoying.   
> Same thing for FXO-to-FXO bridges.
> 
> I figured out today why and fixed it.  Some proprietary voicemail  
> systems (and probably tie-lines, too) like to use DTMF tones instead  of 
> standard ground/loop/kewl whatever signaling.  Our key system was  
> programmed to use such DTMF tones instead of the usual analog  signaling 
> on those ports. (I think it was program 31 on our Toshiba  DK40i)  
> Asterisk of course ignored those, but the other systems used  those for 
> line signaling (including our previous 3rd party system).
> 
> Amusingly, I know now why for years we kept hearing loud DTMF tones  
> when our branch office picked up their phones.  Their system, too,  was 
> configured to have those analog lines be connected to a voicemail  
> system and not to a FXO port on a T1 CSU.
I've just come across a similar problem with a more modern SpliceCom 
hybrid PBX. We have an * system connected to two analog (FXS) ports via 
a couple of Sipura SPA3000 ATAs, and we thought the Sipuras were failing 
to detect call termination.  Turns out that the default behaviour of an 
FXS port on this PBX is *never* to hang up.

jd

-- 

John Daragon                                          john@argv.co.uk
argv[0] limited               (Asterisk implementation & consultancy)
Lambs Lawn Cottage,  Staple Fitzpaine,  Taunton,  TA3 5SL,  UK
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