[Asterisk-Users] Problem about outgoing calls with verizon.

[Rich Adamson]

> I have met a very strange problem. We use a Asterisk PBX connected with two rollover 
PSTN phone line
> provided by Verizon by Digium TDM cards. The incoming calls are always OK. But when I 
make outgoing calls,
> sometimes it works, sometimes it just get a busy tone, doesn't work at all. The 
strange thing is that when I use the
> same server with SBC lines perviously, it worked fine.
>  
> What is the problem here? This drives me crazy.

Asterisk is dialing the number before the central office is ready to
accept it. Just add a "w" in the dial string like this:
 exten => _9XXXXXXX,1,Dial(Zap/4/w${EXTEN}) 
Each "w" is worth about a 1/4 to 1/2 second delay. If one doesn't fix
the problem, try two or three.