[Asterisk-Users] alternative FXO gateway to Mediatrix 1204?

[Peter Lawrence]

I bought a couple of Mediatrix 1204's a few of months back.  (Perceived
advantages were relatively low overall cost and size per port, and
it isn't nearly as vibration sensitive as a PC would be.)

Rich Adamson's review from Feb 1 is comprehensive, and the only thing I'd
like to add is this:

One "feature" of these units that absolutely infuriates me is its
behavior for an incoming PSTN call:

1) upon sensing an incoming PSTN call, it goes off-hook (after
approximately two rings)
2) then and only then, it sends an INVITE to the pre-programmed SIP URL
3) if the user agent on the other end doesn't respond with an OK, it
eventually plays a fast busy to the PSTN caller

This seems so wrong.  Shouldn't a more correct implementation be to send
an INVITE as soon as the PSTN ringing voltage is detected, and if and only
if the user agent on the end OK's should it go off-hook?  There's no sense
in going off-hook unless there's a SIP phone ready and able on the other
end to answer it.

Can anyone recommend a FXO gateway product that does behave in this "more
correct" manner?

Does anyone know if the new Sipura SPA-3000 can be configured to do this?

Thanks.