4 ms·
Does this authentication rely on devices, or is the authentication at the carrier level?
by microcolonel 7y ago
Does this authentication rely on devices, or is the authentication at the carrier level?
- carriers 7y agoIt's at the carrier level. I believe that at least some part of it is noticing that the calling number is a number that doesn't exist. For example AT&T might be given phone numbers 555-0000 through 555-1000, and they know they've only actually given out 555-0000 through 555-0782, but the caller ID claims the number is 555-0999. They can tell it's not a legitimate call because that number couldn't be making an outgoing call because it's not assigned. I don't think that's all of it by any means, but there are a number of ways that the carriers can tell that some percentage of the calls are bogus without having to ask the receiver if they want to receive it.