Followup British Telecom outage reason

Christian Kuhtz christian at
Mon Nov 26 09:47:24 UTC 2001

> This icky tradeoff is why new (as in pre-IPO in some cases) vendors can
> still get a fair test in existing networks.  Eng&Ops type people have
> told me more than once that they thought $NEW_ROUTER_VENDOR could be a
> good investment simply because nearly 100% of their engineering resources
> would be dedicated to making their small number of customers happy, and
> being a larger customer amongst a small set increased this advantage even
> more.

.. which is certainly true until small $NEW_ROUTER_VENDOR IPO'ed or
otherwise grew into not-so-small $NEW_ROUTER_VENDOR, as we have all
witnessed on numerous occasions.   At which point, they're all the same
again.  You only gain an advantage for a limited amount of time.  There are
costs attributed to this as well which need to be realized.

> The big challenge at an established router company is in management of the
> competing priorities more than in management of, or doing of, engineering.

And there also is a business reality.  If you get almost everything right,
most people are happy with that.  Few people demand, need, and can afford to
pay for perfection.

In fact, one could argue that it is poor design to rely on anything to
operate perfectly 100% of the time.

Now, if lack of infrastructure realiability can harm human life you may feel
differently, but that isn't the case for most of us at the present time.

We can sit here all day long and argue back and forth for strategies from
multiple vendor based networks to why single source offers advantages to why
bla bla is cool.  The bottom line is that there is no free lunch here.  If
you want perfection, you will pay for perfection either in house or for your
vendor or lost revenue or all of the above.  And sometimes business cases
cannot support perfection.  The trade-off that has to be made here is how
much "slack" you can get away with while still making your customers happy
and at the same time supporting your business case.  Anything else has no
long term viability.  From an engineering perspective this view certainly
stinks, but when you take into account business realities engineering's
perspectives may be an illusion.   It's the old wisdom of 'pick any two:
cheap, fast, reliable'.

Faults will happen.  And nothing matters as much as how your prepare for
when they do.


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