5 ms·

I'm not sure I follow. If you've ended the call, and you call the bank number on your card, how exactly would the call get routed to the scammers?

by cbg0 7y ago

bluGill 7y ago
It only works in the UK where the phone call only ends after both sides hang up. The idea is you can hang up go to a different room and resume the conversation. The results are this fraud is possible. I believe no other country has that feature.
- acqq 7y ago
  > I believe no other country has that feature. I'm sure there are other European landline phone systems which behave the same. I don't know about the U.S.
  - cbg0 7y ago
    Definitely not the case for Romania. Even though I haven't used a landline in over a decade, if either party would hang up, the call would end.
- lb1lf 7y ago
  We used to have this in Norway when I was a kid; I still remember when I found out by accident - it felt like I had been let in on some big secret.
  - Moru 7y ago
    In Sweden both sides had to hang up, not sure how it is now. My mother used it for kids prank calling. She just left it open until the parents came home and wanted to call, then she explained that their kid had been prank calling us.
- bregma 7y ago
  Definitely used to be the case in Canada. The caller had to hang up: if the receiver hung up it took a (something like 20 second) timeout before the call would terminate. We did used to use that to move to another extension in our house. Note to kids: we used to have our phones anchored to the wall with these coiled ropes so you couldn't walk away with them To counter that, we had multiple phones in various rooms of the house. They also made the phones so big the wouldn't fit in your pocket as another way to prevent stealing them. They didn't have screens because the vacuum tubes drew too much current and they would get too hot when pressed to your ear.
  - mannykannot 7y ago
    Here's a report of what looks like a recent case of a scam using this 'feature' in Canada: https://www.cbc.ca/news/canada/ottawa/line-in-trapping-technology-1.5387822 https://www.cbc.ca/news/canada/ottawa/line-in-trapping-techn...
- outworlder 7y ago
  > I believe no other country has that feature. Some locations in Brazil worked like that, depending on which timeframe we are talking about. Pretty annoying. I guess this depends on the equipment used, not the country.
- erikbye 7y ago
  Norway had it, maybe still, have not touched a landline for decades.
techsupporter 7y ago
The United Kingdom phone system has what is called "far-end supervision" where the circuit-switched landline system will only disconnect the call from the receiving caller if the phone where the call originated hangs up. This trick only works if the receiving caller is on a landline. It will not work on mobile phones.
- __blockcipher__ 7y ago
  Sounds like the perfect attack to target against the elderly, who presumably might be more likely to have landlines
- StillBored 7y ago
  This used to work in the US too. Not sure if it still does.
  - techsupporter 7y ago
    Only some phone systems in the western part of the US had far-end supervision, so far as I am aware. (This is why movies and TV shows from in and around Hollywood show conversations where the caller hangs up and the callee hears a dial-tone. The phone systems in most of California had only far-end supervision. Tom Scott has a good video on this[0].) Most of the US uses either near-end, where the recipient hanging up will end the call, or both-end supervision, on POTS/landline systems. 0 - https://www.youtube.com/watch?v=bUIiUXvnkUQ https://www.youtube.com/watch?v=bUIiUXvnkUQ - This video was filmed at the excellent Museum of Telecommunications in Seattle, located in a CenturyLink switching office. When travel is available again, I encourage all phone geeks to come here and check it out.
- romwell 7y ago
  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?
  - 7y ago
grey-area 7y ago
Not sure how it works, I haven't tested it but assume in the UK at least on landlines that both parties must hang up to break the connection. https://forums.theregister.co.uk/forum/1/2009/09/19/phone_disconnection_scam/ https://forums.theregister.co.uk/forum/1/2009/09/19/phone_di...
chrisseaton 7y ago
They play the sound of someone hanging up, then play the sound of a dial tone, and you dial again, not having hung up yourself.
deleted 7y ago
[deleted]

I'm not sure I follow. If you've ended the call, and you call the bank number on your card, how exactly would the call get routed to the scammers?

by cbg0 7y ago

I'm not sure I follow. If you've ended the call, and you call the bank number on your card, how exactly would the call get routed to the scammers?

bluGill 7y ago

It only works in the UK where the phone call only ends after both sides hang up. The idea is you can hang up go to a different room and resume the conversation. The results are this fraud is possible. I believe no other country has that feature.

acqq 7y ago
> I believe no other country has that feature. I'm sure there are other European landline phone systems which behave the same. I don't know about the U.S.
- cbg0 7y ago
  Definitely not the case for Romania. Even though I haven't used a landline in over a decade, if either party would hang up, the call would end.
lb1lf 7y ago
We used to have this in Norway when I was a kid; I still remember when I found out by accident - it felt like I had been let in on some big secret.
- Moru 7y ago
  In Sweden both sides had to hang up, not sure how it is now. My mother used it for kids prank calling. She just left it open until the parents came home and wanted to call, then she explained that their kid had been prank calling us.
bregma 7y ago
Definitely used to be the case in Canada. The caller had to hang up: if the receiver hung up it took a (something like 20 second) timeout before the call would terminate. We did used to use that to move to another extension in our house. Note to kids: we used to have our phones anchored to the wall with these coiled ropes so you couldn't walk away with them To counter that, we had multiple phones in various rooms of the house. They also made the phones so big the wouldn't fit in your pocket as another way to prevent stealing them. They didn't have screens because the vacuum tubes drew too much current and they would get too hot when pressed to your ear.
- mannykannot 7y ago
  Here's a report of what looks like a recent case of a scam using this 'feature' in Canada: https://www.cbc.ca/news/canada/ottawa/line-in-trapping-technology-1.5387822 https://www.cbc.ca/news/canada/ottawa/line-in-trapping-techn...
outworlder 7y ago
> I believe no other country has that feature. Some locations in Brazil worked like that, depending on which timeframe we are talking about. Pretty annoying. I guess this depends on the equipment used, not the country.
erikbye 7y ago
Norway had it, maybe still, have not touched a landline for decades.

techsupporter 7y ago

The United Kingdom phone system has what is called "far-end supervision" where the circuit-switched landline system will only disconnect the call from the receiving caller if the phone where the call originated hangs up. This trick only works if the receiving caller is on a landline. It will not work on mobile phones.

__blockcipher__ 7y ago
Sounds like the perfect attack to target against the elderly, who presumably might be more likely to have landlines
StillBored 7y ago
This used to work in the US too. Not sure if it still does.
- techsupporter 7y ago
  Only some phone systems in the western part of the US had far-end supervision, so far as I am aware. (This is why movies and TV shows from in and around Hollywood show conversations where the caller hangs up and the callee hears a dial-tone. The phone systems in most of California had only far-end supervision. Tom Scott has a good video on this[0].) Most of the US uses either near-end, where the recipient hanging up will end the call, or both-end supervision, on POTS/landline systems. 0 - https://www.youtube.com/watch?v=bUIiUXvnkUQ https://www.youtube.com/watch?v=bUIiUXvnkUQ - This video was filmed at the excellent Museum of Telecommunications in Seattle, located in a CenturyLink switching office. When travel is available again, I encourage all phone geeks to come here and check it out.
romwell 7y ago
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?
- 7y ago

grey-area 7y ago

Not sure how it works, I haven't tested it but assume in the UK at least on landlines that both parties must hang up to break the connection. https://forums.theregister.co.uk/forum/1/2009/09/19/phone_disconnection_scam/ https://forums.theregister.co.uk/forum/1/2009/09/19/phone_di...

chrisseaton 7y ago

They play the sound of someone hanging up, then play the sound of a dial tone, and you dial again, not having hung up yourself.

deleted 7y ago

[deleted]