Inter-ISP/Telco/X.25 security procedures?

>> Please see Clifford Stoll's book The Cuckoo's Egg for a description
>> of tracking an intruder across various PSTN, PSDN and Internet providers.
>> I haven't seen a better description of the process.

And there were, what?, three US ISPs back then?

And when Stanford was getting hacked, where was BBN...
Answer: right on the Stanford campus, in Stanford buildings!

We don't have the same Internet architecture as we had
during The Cuckoo's Egg era.

I was sort of wondering how long it would take for someone to send this
kind of a response.

I suppose my question should have included the phrase "current solutions"
or equivalent.

Still hoping for some good answers....

Thanks.
Rajesh.