I need the surge protection on the incoming circuits, right at the
demark point. I have several lines including POTS voice lines, POTS
dial in modem lines, VDSL, ADSL, and T1 circuits. Is there a surge
protector that will protect all of the above lines without degrading
performance?
If in North America, that protection must be installed, for free, by
your telco. Protection that will be as good as the earthing you have
provided.
The same protector typically uses for voice is also used for those
other lines. Each wire in each cable connects to earth via a
protector. That protector must be low capacitance so as to not
degrade signals.
The connection to single point earthing must be as short as
practical (ie 'less than 10 feet'). Therefore, for that protection
to be effective, it must be adjacent to all other incoming utilities.
Each utility must also make that same short connection to the same
earthing electrode.