A similar concept applies in the SS7 [1] network, B-number [2] analysis, but is not used that way, as telco's have no way to properly manage which switches may

A similar concept applies in the SS7 [1] network, B-number [2] analysis, but is not used that way, as telco's have no way to properly manage which switches may originate which numbers as they are portable. They just do routing and trust the sender is allowed to have the number presented in the SS7 packet. [1] - https://en.wikipedia.org/wiki/Signalling_System_No._7 https://en.wikipedia.org/wiki/Signalling_System_No._7 [2] - https://en.wikipedia.org/wiki/Called_party https://en.wikipedia.org/wiki/Called_party