Sounds wonderfully abusive!
So, say, if I called you and you picked up, I would be able to prevent you from calling anyone else by not hanging up indefinitely?
Just great. Will the system not disconnect if you dial 999, too?
So, say, if I called you and you picked up, I would be able to prevent you from calling anyone else by not hanging up indefinitely?
Just great. Will the system not disconnect if you dial 999, too?
Originally there was a grace period because of pulse dialling. Each "pulse" is actually a hangup - so the system had to tolerate that hangup != disconnect. But the grace period was far too long, and eventually end-users adopted it as a feature - if you wanted to take this on your bedroom phone instead of your hallway phone, you could hang up the phone, go up stairs, and pick up the bedroom phone.
So now we have two problems. One is that the bug has been adopted as a feature. The other is that precisely because of 999/e911 systems, the phone system is incredibly backwards compatible. Most exchanges still support pulse-dialling - it's never dropped intentionally (some exchanges don't, because they're too modernized. But it's not a conscious "lets turn this off now" thing.)
There has been a move in recent years to reduce the grace period, precisely because of this abuse. But until it's dropped short enough to be a non-issue, my advice for anyone who thinks a call is suspect, is to call the talking clock (123 in the UK). It is a paid service, but I don't like bothering the operator for such things. But if you call 123, and reach your bank, you know summat's up.
No no no no no.
Hang up and use another phone. End of. Any advice that you call another number first or whatnot is bad advice. If such advice got widespread, what would scammers do?
Obviously, they would have a DTMF decoder on the other end and they would patch the call through to the number you called. These are sophisticated people who send fake security officers to people's houses to "pick up the compromised card". Call forwarding is trivial.
Good that the UK is moving away from this "feature".
(I still remember that to take a call on another phone, you could just leave the receiver up on the phone you too the call on, provided you're not too lazy to hang it up later).