[c-nsp] MTBF for Cisco products

[Ted Mittelstaedt]

> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net
> [mailto:cisco-nsp-bounces at puck.nether.net]On Behalf Of Seth Mattinen
> Sent: Tuesday, November 27, 2007 10:46 PM
> Cc: Cisco-nsp
> Subject: Re: [c-nsp] MTBF for Cisco products
> 
> 
> Ted Mittelstaedt wrote:
> > For a $20K device you better damn well understand it IS low.
> > 
> > Name me one single automaker out there who could get away with
> > building a car that would stop running after 4.5 years.
> > 
> > Even the disk drive manufacturers - Seagate for one - warranty
> > their stuff longer.  And it has moving parts!
> > 
> 
> Maybe the MTBF includes chassis fans... sometimes they eat it early.
> 

You can get high quality Chassis fans.  DEC used chassis fans in the
Vax that had MTBF of hundreds of thousands of hours.  The difference
is not in the bearings, sleeve or ball, as most people who don't know
any better think.  The difference is in the quality of the dust seals.
Regular fans have very poor dust seals and as a result the bearings
get choked up and they fail quickly.  Expensive fans have good dust
seals and can be literally coated with dust to where the entire fan
is brown and still work perfectly.

Ted