It does not ease the situation WHEN your bits transit one provider's
backbone (whom you chose to assure redundancy) does ultimately receive
transit (at times such transit is not for long distances..) from a yet
another whose infrastructure is now effected. I am not suggesting however,
that is the case here.. AT&T is investigating.
Yeah, that's one reason why I stopped including the name of the carrier
in most fiber cuts. It was getting too hard to tell who was who with
all the swapping, leasing, sub-leasing, etc. Cable&Wireless is paying
Level 3 $670 million for pieces of its fiber. GTE/BBN paid Qwest a ton
for pieces of its fiber. AT&T, Sprint, MCI/Worldcom fiber overlaps so
much its hard to tell them apart in some places. Qwest and IXC keep
digging up other people's fiber, which would indicate their new fiber is
being placed very close to other fiber. The non-facilities based carriers
sometimes do better if they can guess which carriers have non-overlapping
facilities, and buy from multiple physical facilities. But its not uncommon
to see a dozen large ISPs have problems when someone trashes an interesting
SONET ring somewhere, like Herndon/Mclean this morning.
All the good right-of-ways are already taken. Heck, last year I was on
some beautiful Caribbean islands with populations less than 100 people. We
found both a backhoe and a cut telephone cable on them.
In ten years (I ordered my first circuit in 1989), I've never gotten a
good, coherent answer why any of my diversely, redundent circuits were
both out-of-service at the same time due to the same event. Lots of
credits, lots of apologies, but never a straight answer why something
that should never happen, modulo the end of the world, happened.
[details about fiber mangling cut (no pun intended ]
In ten years (I ordered my first circuit in 1989), I've never gotten a
good, coherent answer why any of my diversely, redundent circuits were
both out-of-service at the same time due to the same event. Lots of
credits, lots of apologies, but never a straight answer why something
that should never happen, modulo the end of the world, happened.
Sometime in 1991 or so, when we were moving the SURAnet backbone from
university campuses (campii?) to collocation space in MCI POPs throughout
the southeast, I was talking to one of the MCI techs about the physically
diverse T1s that MCI was contracted to deliver. He said if the same
person engineered the routing for the circuits at the same time (which
would only be done if it was specified on each order), then we might
get lucky. Even if diversity is engineered in at first, shuffling
circuits on cross connects and such would decrease the likelihood over
time (an amazingly short amount of time) - and he also indicated that
after a while, it was unlikely that anyone would even be able to
determine on demand the actual path that any given circuit takes... :-/
I certainly hope that the systems for tracking this have improved,
and also that they keep better track of DS3s and SONET better than
they do DS1s.... but I'm skeptical.
have fun out there,
dave (now celebrating my 8th year
of retirement from running
networks
Sometime in 1991 or so, when we were moving the SURAnet backbone from
university campuses (campii?) to collocation space in MCI POPs throughout
the southeast, I was talking to one of the MCI techs about the physically
diverse T1s that MCI was contracted to deliver. He said if the same
person engineered the routing for the circuits at the same time (which
would only be done if it was specified on each order), then we might
get lucky. Even if diversity is engineered in at first, shuffling
circuits on cross connects and such would decrease the likelihood over
time (an amazingly short amount of time) - and he also indicated that
after a while, it was unlikely that anyone would even be able to
determine on demand the actual path that any given circuit takes... :-/
Naturally - they make a lot more money lying to you and then paying the
penalty when they get caught. Like 100% SLAs - a provider who offers a
100% SLA *knows* they can't actually meet their guarantee, so they budget
in $X for payment of the penalties. And sometimes they even make the
process ridiculous to get your refund.
Of course, we don't know any providers that would do something like that,
do we?
I certainly hope that the systems for tracking this have improved,
and also that they keep better track of DS3s and SONET better than
they do DS1s.... but I'm skeptical.
So am I. :((
I know *exactly* which cables my E1s/T1s/DS3s/etc. are using - but I ain't
got nearly as many as an MCI or a UUNET. I hear it's easier to do if you
don't have a bazillion of them. (OTOH, perhaps one should not use a
provider that is so big the provider's engineering staff cannot even manage
their own network.)
dave (now celebrating my 8th year
of retirement from running
networks
Congrats.
TTFN,
patrick
I Am Not An Isp - www.ianai.net
ISPF, The Forum for ISPs by ISPs, <http://www.ispf.com>
"Think of it as evolution in action." - Niven & Pournelle
(No, I still don't have enable.)
(OTOH, perhaps one should not use a