[Asterisk-Users] no dial tone when dialing out on vonage

[Imran Akbar]

Hi,
    I'm trying to dial out on a vonage line connected to a zap channel 
using stuff like:

exten => 200,1,Dial(Zap/2/${EXTEN})
but it doesn't work - when i dial in the extension, i can see on a phone 
connected to the same line that it's gone active - but there's no 
dialtone.  also tried adding a wait period before accessing the line and
exten => _XXXXXXXXXX,1,Dial(Zap/2/${EXTEN})
to no avail.

what's goin on?

Thanks,
Imran