DS> Can telstra tell if you are using a non-austel
DS> approved modem even though it isn't doing any damage?

CM> No, they can't tell,

True.

CM> but how do you know your modem hasn't done any damage ? just
CM> because your line is ok doesn't mean the exchange is undamaged.

If it keeps killing the line interface, you will find out Chris.
One obvious indication is that your phone line stops working.

CM> I was having a chat to the designer (netcomm) who is designing
CM> a new PCMCIA modem for netcomm and he said that in order to pass
CM> (one) Austel test modems are fried (electricaly) with about 12,000
CM> vac and they must not pass any more than 200 vac down the phone
CM> line, if they do then they fail (and are not approved).

And non austel approved modems are normally FCC approved and that
requires them to pass a similar test with a lower voltage, which is
STILL perfectly adequate since it requires it to survive a 1.5KV test.

And the phone exchange line interfaces have to
be able to survive lightning and stuff anyway.

CM> If telecom (telstra) get constant faults on one circuit (ie yours for
CM> instance) then they WILL search for a cause and trace it back to your
CM> line and come out to inspect your line, and if they find a non-austel
CM> approved modem (or other device) connected then they (austel) can give
CM> your a rather large (4 figure) fine and telstra would probably also take
CM> a dim view of it and charge you for repairs to the exchange circuit.

Yes, its theoretically possible. Pity that you cant actually nominate
too many non austel approved modems ever getting into that situation tho.
And the reason they dont is very very simple, the FCC approval requirements
are perfectly adequate to ensure they dont kill the exchange.

Even in a worst case scenario where your PC goes kaput and puts the full
240V onto say the bus connector of the internal modem, the 1.5KV voltage
isolation to the phone line itself ensures no 240V on the phone line.

Ditto with say an external modem if the plug pack fails and puts 240V
onto the modem. And if you are paranoid there is no reason whatever why
you cant use an Austel approved plug pack and a non austel approved modem.

--- PQWK202