[Asterisk-Users] No ring on extensions

[Don Pobanz]

On Monday, April 28, 2003 11:58 PM, Surfer Dude 
[SMTP:swell at labranch.com] wrote:
>
> So, is the 90v constant during ring?  Or is it intermittent?  Does 
the phone
> "see" the 90v then make a periodic sound?  In other words does the 
90v
> occilate?  Is it possible to change the sound of the ring through *
> (I figured out what people ment by * (smile)) or is the ring sound a 
funtion
> of the phone?
>
> Thanks,
> Jason
>

Back at the local phone company the normal pots line had 48 volts dc 
for an on-hook phone.  On top of that was a 50 volt 20 Hz AC signal 
which was present only when the phone was to ring. The most common 
cadence for that is 2 seconds on (ringing) followed by 4 seconds off. 
This use to be what would ring the phone when there were only 
mechanical ringers. To vary the cadence (or distinctive ring) requires 
that the 50 volt ac be turned off and on in the desired cadence. The 
electronic ringers are 'told' the same way when to ring. The only 
difference is that they generate their own sound.

Yes it is possible to change the ring through *. I don't recall the 
exact syntax but it is something like
exten => _2xx,1,dial(Zap/16,r1)
where r1 = distinctive ring number 1
           r2 = distinctive ring number 2
           r3 = distinctive ring number 3

Don Pobanz