>> And to respond to DLR's concern about the line getting 'answered by
>> the wrong machine', the point is that the _box_ answers the call and
>> routes it appropriately. 'Distinctive ringing' from the telephone
>> company isn't required at all.
> Sorry for jumping in, but how do those boxes work?
> ...does the box simultaneously listens [sic] to the incoming call
> to tell if it's fax or voice, and also play a ring tone so, in case
> it's a human calling, the caller thinks the phone is still ringing?
Yes.
Moreover, the 'dummy' ring tone generated by the box is customisable. You can set it to match the tone normally produced by your telephone company or you can make it something different, in which case the alert caller recognises that he is through to another level of ... ringingness.
Cheers,
Henry