> As we left it struck me that this cut was not if, but when. And more cuts
> like it. There was no protection for the cable, no markers of the cable
> location.
One of the interesting things about the startup of Wiltel was pulling fiber
through decommisioned gas pipelines; not only do you get a 1/4" steel
backhoe fade margin, but you get scary yellow signs that say "DANGER: HIGH
PRESSURE NATURAL GAS LINE"; cut a piece of innerduct and your boss yells at
you. Bust a gas pipeline and they can bury what's left of the offender in a
thimble - if they can find it.
Gee, makes a good case for putting innerduct inside conduit and putting
gas through it just to discourage BIFF. 
The thing that doesn't make sense to me in all of this is that SONET
is supposed to be built as RINGS. With a Service side and a Protect side
to each switch. BIFF should, in theory, only take out one or the other,
but not both. WHY, with what we pay these carriers every month, do they
not divergent-path route these critical wide-area links so that this isn't
fatal?
Anyone from MFS/WilTel/WorldCom/UUNET/AlterNet/whoever-else-they-buy-but-
still-don't-fix-what-they-have care to comment?
Owen DeLong
Exodus
I suppose because you account for about 0.0001% of their total revenue.
Hey, youre lucky for our accountabilty you could shove a few extra naughts
in the middle ;-(
At the end of the day, are you going to cancel all your circuits with
them? I doubt it - I have been tempted with certian telcos but the cost
and hassle, all *after* the downtime has occured ain't always worth it. I
bet the telcos are betting on that.
Regards & Good luck with your diveristy!
aid
The usual response is that carriers are over-provisioning lines (more than
50% of capacity used). Voice links usually get priority during rerouting;
perhaps all the Tier-1 internet links are being provisioned in the "above
50%" section of the fiber, since Internet outages aren't as costly as voice
outages.
However, what if Backhoe Fade is far more common than advertised, and we
only find out about cuts when BOTH sides of the rings are hit? Is there
any practical way to measure/detect SONET failover from an endpoint?
Stephen
Am I the only one who's a cables and switches weenie enough to know
that the telco's _already do this_? Large numbers of local multi-pair
trunking cables are pressurized with nitrogen, and they put pressure
drop alarms on them, so they know if one takes a hit.
Cheers,
-- jra
The 144 fiber strand WorldCom cable between DC and NYC doesnt do this. It
carries Sprint, Cable and Wireless and a few other telco's as well.
--stb
Am I the only one who's a cables and switches weenie enough to know
that the telco's _already do this_? Large numbers of local multi-pair
^^^^^^^^^^^^^^^^
trunking cables are pressurized with nitrogen, and they put pressure
drop alarms on them, so they know if one takes a hit.
pressurized nitrogen is usually done to keep moisture out, not so that
they can monitor pressure loss. pressure loss in a fed, very long,
pipe is an extremely local phenomenon anyway. i think there are
spooks at some black agencies that monitor against tapping this way.
but in practice, nitrogen pressurization is only done for copper.
Yes. I know. 
I'm told they really do pressure loss monitor the local stuff, though,
even if more for dryness purposes than cable-break.
Cheers,
-- jra