telephone hackers - can we upload something?

On 20/07/2018 23:28, J. P. Gilliver (John) wrote:
(This applies here in UK - probably there as well.) If only one party
hangs up, the connection remains open - for a time. I presume it's to

If the caller hangs up the call disconnects immediately.
But if the called person hangs up there is a timeout before the call
disconnects.


prevent _accidental_ termination of a call due to noise on the line, or
similar. (It _can_ even be useful - lets you hang up one 'phone and pick
up another, say if one handset's battery runs out, or you want to go to
another one next to your desk or something.) It _does_ time out
eventually, but after quite a lot of seconds. Banging on the rest
_sometimes_ clears it.

If you "bang on the rest" you're probably sending a recall which opens
another outgoing line ready to start building a three way call, or ready
to switch between the two calls.


Unfortunately, it's well known to be misused by evil folk: they'll ring
up pretending to be your bank or whatever, then suggest you hang up and
call the bank using a number _you_ choose. Unfortunately, they keep the
line open - even playing you a recording of the dial tone when you hang
up and pick up again, so you _think_ you're genuinely dialling.

Because of this, I think there are moves in place to force the
telecomm.s companies to prevent it, mainly I think by shortening the
timeout-on-one-party-hangup. In the meantime, the advice is - should you
receive such a call apparently from your bank, though this is unlikely -
that tells you to call them back, to first call some unrelated number,
such as a relative.


--

Brian Gregory (in England).