[Asterisk-Users] Has anyone tried using a Sipura-3000 as an FXO device for *?

[Rich Adamson]

> > The box was truly targeted for the residential user where existing
> > phones interface on one side, the pstn line on the other side, and
> > the default call is sent to the voip interface. Disconnected (or
> > failed) ethernet results in a relay flipping, tying the fxs directly
> > to the fxo. Same with power failure. Nice.
> 
> I think the cut-through from the fxs to the fxo (and backwards) is via
> a digital connection.  In normal use you appear to end up getting hit
> by the digitization delays.  As far as I can tell the relay
> cut-through is only used for power failure.

It's actually a relay, and you can hear/feel it. The cut-through actually 
works by either removing power, or, removing the cat5 cable. However, 
it wouldn't have a clue whether a layer-3 box (including *) were down.

> > Initial tests did not show any signs of echo, very good volume and 
> > audio quality, and would probably be a good choice for small quantities
> > of pstn lines (particularily soho and residential users).
> 
> I still notice some low-volume problems with
> FXO->asterisk->grandstream-bt101 even though I bumped the FXO incoming (and
> outgoing) gains to +12dB.  (To keep calls from the FXO->asterisk->FXS
> a reasonable volume I needed to drop the gain of the fxs port to -15
> (from the factory of -3).
> 
> Somebody with a real phone VU meter needs to have a look at the
> Sipura-3000 FXO.  I can't believe it is off that much.  Might the
> Grandstream BT-101 be really low in volume and I'm just mistakenly
> blaming the volume problem on the Sipura?

That's odd; sort of sounds like BT101 problem. Using C7960's, the 
volume was excellent (without touching anything). Using an analog
set on the fxs port was very "hot", and dropping the fxs gain slightly
improved that to what a non-technical user would suggest is normal.
(I did use a $3500 transmission test set on as well.)
 
> Given the choice between hearing dead air and hearing the tones, I
> think I'd rather hear the tones.  At least I know something is
> happening.

I'd suspect that non-technical users would raise a small issue with the
tone feedback (at least in the US), as their not acustomed to hearing
that on normal calls.

Rich