[Asterisk-Users] Dial out problems with Digium TDM400P card.

[Scott Petersen]

On Tue, Jul 27, 2004 at 03:27:40PM -0700, Malcolm Bader wrote:
> I recently purchased a Asterisk Developer's Kit (TDM) and now have it 
> outfitted with 2 FXO modules and
> 2 FXS modules. I'm not using the X100P modem card that came with the kit.
> I'm having problems with dialing out on my POTS line.
> Successful dial out is intermittent. About 50% of the time the call goes 
> through.
> The other 50% it is dialing the wrong number. ( I can hear the error 
> message from the phone company)
> If I dial 98531212 asterisk reports it is dialing 8531212 but I think it 
> is really dialing 531212, sometimes.
> It is random with maybe 2 or 3 successful calls followed by 2 or 3 
> unsuccessful calls.
> 
> Part of extensions.conf :
> exten => _9NXXXXXX,1,Dial(Zap/1/${EXTEN:1})
> exten => _9NXXXXXX,2,Congestion
> 
> 

I just finished resolving this exact issue with my setup. There appears to be a timing issue with the TDM400 cards and the zaptel drivers such that the first digit doesn't always go through properly.

The solution is to add a wait command in the dial string prior to dialing the number. You will notice the w entry prior to the ${EXTEN).

exten => _9NXXXXXX,1,Dial(Zap/1/w${EXTEN:1})
exten => _9NXXXXXX,2,Congestion

This has worked 100% for us. Not a single call has been misdialed in the last week since this was implemented.

Cheers
Scott Petersen
Xavier Solutions Inc.
scott (at) xaviersolutions.com