I've yet to read a good explanation of why the telcos permit CLID faking and reinjection of apparently local CLID by overseas inputs.
I'm assuming there's a technical and/or willpower reason or some counterfactual like VOIP depends on it.
Even just flagging it would help. Or, rejecting numbers they can know lie inside their own routing architecture, or asserts within their own number plan where the CLID does not match.
Morally it's like BCP38 in the customer facing internet systems: reject customer input they don't pay you to assert.
I'm assuming there's a technical and/or willpower reason or some counterfactual like VOIP depends on it.
Even just flagging it would help. Or, rejecting numbers they can know lie inside their own routing architecture, or asserts within their own number plan where the CLID does not match.
Morally it's like BCP38 in the customer facing internet systems: reject customer input they don't pay you to assert.