N+? redundancy

Mon Apr 18 16:07:06 UTC 2005

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.

----- Original Message -----
From: jmalcolm at uraeus.com
Date: Saturday, April 16, 2005 2:00 pm
Subject: N+? redundancy

> 
> Michael.Dillon at radianz.com writes:
> >In my opinion, the following rule of thumb is reasonable.
> >
> >1 path is enough for a site/enterprise that shuts 
> >down its services evenings and weekends.
> >
> >2 paths is enough for a site/enterprise that provides
> >a 24 hour, 7 day per week service.
> >
> >3 paths is enough for a population center with under
> >a million inhabitants.
> >
> >5 paths is enough for a population center with over
> >a million inhabitants.
> >
> >And a very few population centers such as New York,
> >London, Tokyo, and Cheyenne Mountain should probably
> >have more than 5 paths.
> 
> Given that anything larger than a single enterprise has no central
> coordinating body, how is it useful to say how many paths is "enough"
> for a city of any size? Service providers will build as many paths as
> make commercial sense, whatever that may be, and if customers have
> opinions and are willing to back it up with money, they should express
> those opinions to their providers.
> 