18 Jun
2011
18 Jun
'11
2:38 p.m.
On Sat, 18 Jun 2011, Ethan Dicks wrote:
I was not aware that emergency phones in lifts in the
UK were attached
to the PSTN in a way you could gain control of the line. My
understanding (which could be inaccurate, I admit) is that in the
States, either the phone rings an internal maintenance number (for
buildings that are staffed 24/7, and that may be an obsolete practice
by now anyway) or it autodials to some off-site service that may
eventually result in someone being sent to the site. You don't now
nor ever did have a way of getting a dial tone.
No Personal Experience, but I have heard that,
not all autodial systems are completely secure. For example, could it be
possible to drop the party at the other end, without actually dropping the
connection?
"I know! Just tell whoever answers at the offsite service to press 90#"
:-)