Re: One-element vs two-element design

[Scott McGrath <mcgrath () fas harvard edu>]

Point taken, Availability would have been a better term to use.

> From a customers standpoint limited availability of bits is still better
than no bits flowing and in an ideal world your published capacity would
be N rather than N+1.

Appreciate the thoughtful comments

Regards - Scott

                            Scott C. McGrath

On Sat, 17 Jan 2004, Deepak Jain wrote:

> [stuff snipped]
>
> > but the overall system reliability is much higher than a reliable network
> > since a component failure does not equal a functional failure.
>
>
> s/reliability/availabilty.
>
> You meant reliability when comparing a 1 vs 2 engine airplane, but a
> network (from a customer point of view) isn't defined by reliability,
> its defined by availability.
>
> If you are using your backup (N+1) router(s) for extra capacity, than
> you don't fail back to full capacity, but you do have limited availabilty.
>
> Availability/Performance of the overall system (network) is what we all
> engineer for. Customers don't care about reliability as long as the
> first two items are not impuned. (For example, they don't care if you
> have to replace their physical dialup port every hour on the hour,
> provided that they can get in and off in between service intervals --not
> a very reliable port, but a highly available network from the customer
> perspective).
>
> Maybe I am just picking on semantics.
>
> Deepak