You must have missed my half joking posting on the voice system
outages we've seen (as just one customer of the voice network). In
order to give us 99.999%, Nynex owes us 250 years of flawless service
for the one 22 hour outage I mentioned. Since there have been other
outages to our voice service, I think we're due for a good 1,000 years
of flawaless service to bring us up to 99.999%.
If we hold BBN to the same standards that the telco industry uses to
come up with 99.999%, BBN was up but "a few customers" experienced a
localized outage. This would be brushed off the same as the Illinious
AT&T fire at the POP that took out much of the Chicago suburbs for
about a week. It doesn't count against the 99.999%. (Otherwise AT&T
owes Chicago a couple thousand years of flawless service:).