The 02.12.07 at 23:15, Dylan wrote:
I understand it's practically imposible to do this without the help of the teleco provider.
practially to protecet without the teleco prov. or practially impossible to fake the caller id (didn't tried it but this seems to be possible)
I was thinking of the latter - people here will be able to give better info I expect, but the way I understand it the CLI originates at the exchange the source line is connected to and is used for routing the return leg of the call handshake: so the teleco would need to do the faking, and if it was faked the teleco would need to know so the correct routing can be done.
As I have worked for a big maker of exchanges, I can tell you that what you say is correct. It is the exchange that sets the CLI, and the software in it is not designed for manipulation: I'm not aware that it could be possible, and even if it were the access would be disabled for normal operators. All this means that such a manipulation need a determined attempt high up. -- Cheers, Carlos Robinson