while is suspect the
telco powered
products
site is a humourous hoax, i wondered if there was some grain of
truth behind it. an authoritative-sounding
post
on the
boing boing
hints that there might be. then again, maybe it’s just a more
plausible sounding ruse:
“Every designer of subscriber line equipment has faced
this issue. The ones who survived figured out why you can’t do
this.”“If you try to get DC power off the line, and the impedance of your
line is marginal, the telco will think your phone is off-hook
(looking for dial tone). The telco will, after a few minutes,
unhook your line from the switch. This is self-healing because the
telco goes back to scan those “dead lines” every few minutes. If
you disconnect the offending device, the telco will reconnect your
phone to the switch after a few minutes.”