[Asterisk-Dev] A few driver ideas...

[James Harper]

> > I've had a bit of a look around the datasheets and can't see if
that's
> > possible or not, but nothing obvious leaps out. About zaptel timing,
is
> > the timing supposed to come from the card which is in turn supposed
to
> > come from the [BP]RI interface? Or does the card just need a 1Khz
clock
> > (or something you can derive 1Khz from) on it. And in that case,
would
> > it be sufficient just to use the system timer a-la ztdummy? I assume
> > not, but if you know the reasons I'd love to know!
> 
> The card/chipset needs to have a 1khz timer that fires an IRQ.
> This timer should be derived from the BRI line.
> You cannot easily use a different timing source (like ztdummy) because
> it is not synchronized to the BRI line. I tried this with RTAI
(realtime
> application interface) support for the zaphfc driver.
> 
> >
> > Assuming it can't generate the 1Khz timing, would it still work in a
> > system with another card that could do zaptel timing?
> 
> No.

I'm learning more about zaptel timing than ever before :)

So if you had 3 cards (say 1 PRI, 1 BRI, 1 FXO), the first two can
provide zaptel timing to asterisk because it is generated in them from
the exchange. But for their own signal processing, they need to use
their own internal timing regardless of if asterisk is currently using
it or not, eg the PRI can not make use of the timing from the BRI card.

Is that right?

Thanks

James