
On Wed, 04 April 2001, Stephen Griffin wrote:
> Again, very little reason to need multiple providers if the provider
> is good. If you're concerned about circuit grooming, write it into
> your contract with _severe_ penalties for failure to meet the terms
> of the contract.

Kung Fu flashback sequence:

  In time, you will understand.

Fortunately, lawyers can not change the laws of nature or statistics
no matter what they tell you.  No matter what you write into your
contract, stuff will go wrong.  Car insurance means when you crash
your car, the insurance company pays for a new car.  It does not mean
your car will never crash.  By lowering the deductible, all you are
changing is the premium you pay.  Want a 99% SLA, the premium is $X.
Want a 99.999% the premium is $X+N.  Want 100% the premium is $X+X+N.

VISA (the credit card people) uses two independent providers for its
international network, and has a department of people verifying the
redundancy of their network.

The US Government uses two independent providers for its international
network, and has a department of people verifying the redudancy of the
circuits which "can't go down."  Guess what, NORAD once lost all of its
triple-redundant, diversely-routed circuits due to a carrier mistake.

If you aren't the size of the US Government or VISA (I'm not sure which
has more power) I suspect you won't be able to write penalties more severe
than either of them imposed on the carriers.  And even with those penalties,
circuits still fail due to carrier mistakes.

When I did the math, and paid money for circuits, I discovered for the
premium I paid for a 100% SLA I could often buy two diverse circuits
from two different providers with no SLA for less.  And to cap it off,
the actual reliability of those two circuits was better than the single
100% SLA circuit I would pay extra.




