Denial of service attacks apparently from UUNET Netblocks

I realize this is probably something one learns in Telco 101, which I
haven't taken, but if CNID == Caller ID, wouldn't ANI be *more* useful?

It depends on what you want. A real call trace is more involved. But
if all you are interested in is the billing information, then ANI usually
works. If all you are interested in is the directory number then CLID
works. In general, it is bad news for ISP geeks to play telephone guru,
and bad news for telephone geeks to play ISP guru.

Or does CNID report the number regardless of Caller-ID blocking on PRI

No. Assuming the telco programs the switch correctly, blocked CLID won't be
passed on subscriber lines. Mistakes happen, but don't count on it.

(I'm assuming that CNID == standard Caller-ID as it appears on POTS, and
that ANI == the special service that 800-lines get that *always* reports
the number, regardless of blocking..if I'm wrong, I'll accept the LART.)

The alternative is to become a CLEC, and buy something like a FGB
circuit with ANI or full-fledge SS7 trunks with per-minute usage fees,
aka settlements.

If you only want to pay standard POTS rates for your dialup lines, you
only get standard POTS service. I think the telco's blew it when they
tried to impose per minute fees on ISPs. Rather than thinking up nifty
new services ISPs might want on the lines, and create a demand for
improved lines, the telcos tried ramming through tariff changes for
more money for the same service and ended up losing even more. The
current dialup/packet-switched interface is such a kludge anyway. We've
got to work on getting real packet-switched data service to the home
for a number of reasons, not the least to get rid of this interference
layer between the circuit switched identifier and the packet switched