Not necessarily. The number of paths in a city often has little to do with the providers and how many paths they would like offer, or at least did when they had the money to build. Many times the contraint is not demand but the zoning laws on where paths can be laid. Even if a client demanded and was willing to pay for the diverse paths there can be none available. Thus some times providers simply don't tell what the physical pathways are because they can be no different than the ones the prospective client is already using. Quite simply it is not a problem that the market can solve on its own because the market does not completely own the problem, state and municiple authorities also have a large piece of the game. The number of paths varies widely between cities, and has little to do with demand in those cities for diversity or how critical they might be to the nation as a whole.
Even if a client demanded and was willing to pay for the
diverse paths there can be none available.
When there is demand for something that the market
cannot supply due to political constraints, then there
are political solutions.
The number of paths varies widely between cities, and has
little to do with demand in those cities for diversity or how
critical they might be to the nation as a whole.
If requirements for network path separacy can be communicated
in such a way that people clearly see that it is critical
to the nation (or any other political body) then it is
possible to release additional path opportunities to the
market.
The rules of thumb that I suggested had to do with how
much network redundancy is likely to be "enough network
redundancy". I also didn't supply the numbers to back up
these rules because, to the best of my knowledge, nobody
has studied the risks involved in enough detail to do
analyse this.
I did receive one anecdotal account related to the ice storm
in Montreal back in '98, I believe. It seems that this
city of over 1 million inhabitants had 5 paths providing
electricity to the city and 4 of those paths were knocked
out.
Interestingly, nobody suggested my numbers were too low
or too high. I suppose that is a rough and ready tacit
approval of my rough and ready rules of thumb.
--Michael Dillon
P.S. Let's hope that Jay gets his Mediawiki off the ground
so that we can develop other "best practice" rules in a
format that makes it easy to use them for training new people
coming into the industry.