4 ms·

Regarding caller ID spoofing part of these robocalls... I would think the telco knows the number of each connected phone line, why can't they overwrite whatever

by tomc1985 8y ago

Regarding caller ID spoofing part of these robocalls... I would think the telco knows the number of each connected phone line, why can't they overwrite whatever number the caller supplies?

toast0 8y ago
Historically, spoofing came from people with Primary Rate Interfaces (PRI, aka calling over T1), where you got to set the outgoing caller id because you might be running inbound calling separate from outbound calling, and you were presumed to know what you're doing. In the last 20 years, give or take, the spoofing comes from VoIP carriers that are interconnected to the traditional telcos where you're receiving the calls. Your carrier has no idea which customer of the other carrier is making the call, only what the other carrier told them. The other carrier may also be passing through calls from another carrier -- there's a lot of traffic mixing going on.
nitrogen 8y ago
A "phone line" is kind of an outdated concept. Even traditional call centers had many numbers carried as digital data over something like a T1 line, and nowadays how do you connect a "line" to a call center running VoIP over a business-grade cable modem connection? The "line" is just metadata, like caller ID.
deleted 8y ago
[deleted]
bluGill 8y ago
They don't know. the phone system was designed on a trust the caller to not lie system...
munk-a 8y ago
What if a call is originating from AT&T and going to a Verizon number, AT&T could mark the number as "tots legit" and then Verizon would be unable to tell if AT&T was lying or not, in fact if one company started clamping down then another company might start openly acting as a haven for these sorts of calls and making a lot more money by being the only option to look legit... Finally, if these calls are originating overseas you might have to go through the chinese government to actually try and force a bad acting telco to start cracking down, that sort of pressure would take the US government - while tech companies have some pull overseas a lot of the local service companies (including probably AT&T) have nothing to pressure the chinese government with.
MiddleEndian 8y ago
They could pass you the originator information and refuse to complete calls from networks that don't give them that information. But they won't because that's less money for them
downrightmike 8y ago
Ideally there would be a ANI number, which should be the originating number. Which is used to know who to bill as the call goes from telco to telco. Most phones don't use this, it isn't required and can also be spoofed. Then there is the CSID which is what shows up on your caller ID and that can be set to whatever we want. What we really need is to force ANI because that is transmitted before the first ring and the CSID is after the second ring. But hardly anyone wants to have a ANI set, especially the spammers.

Regarding caller ID spoofing part of these robocalls... I would think the telco knows the number of each connected phone line, why can't they overwrite whatever number the caller supplies?

toast0 8y ago

Historically, spoofing came from people with Primary Rate Interfaces (PRI, aka calling over T1), where you got to set the outgoing caller id because you might be running inbound calling separate from outbound calling, and you were presumed to know what you're doing. In the last 20 years, give or take, the spoofing comes from VoIP carriers that are interconnected to the traditional telcos where you're receiving the calls. Your carrier has no idea which customer of the other carrier is making the call, only what the other carrier told them. The other carrier may also be passing through calls from another carrier -- there's a lot of traffic mixing going on.

nitrogen 8y ago

A "phone line" is kind of an outdated concept. Even traditional call centers had many numbers carried as digital data over something like a T1 line, and nowadays how do you connect a "line" to a call center running VoIP over a business-grade cable modem connection? The "line" is just metadata, like caller ID.

deleted 8y ago

[deleted]

bluGill 8y ago

They don't know. the phone system was designed on a trust the caller to not lie system...

munk-a 8y ago

What if a call is originating from AT&T and going to a Verizon number, AT&T could mark the number as "tots legit" and then Verizon would be unable to tell if AT&T was lying or not, in fact if one company started clamping down then another company might start openly acting as a haven for these sorts of calls and making a lot more money by being the only option to look legit... Finally, if these calls are originating overseas you might have to go through the chinese government to actually try and force a bad acting telco to start cracking down, that sort of pressure would take the US government - while tech companies have some pull overseas a lot of the local service companies (including probably AT&T) have nothing to pressure the chinese government with.

MiddleEndian 8y ago

They could pass you the originator information and refuse to complete calls from networks that don't give them that information. But they won't because that's less money for them

downrightmike 8y ago

Ideally there would be a ANI number, which should be the originating number. Which is used to know who to bill as the call goes from telco to telco. Most phones don't use this, it isn't required and can also be spoofed. Then there is the CSID which is what shows up on your caller ID and that can be set to whatever we want. What we really need is to force ANI because that is transmitted before the first ring and the CSID is after the second ring. But hardly anyone wants to have a ANI set, especially the spammers.