SONET ring questions

Sat Oct 17 05:34:52 UTC 1998

> For total system uptime
> 90.0% (one nine or less) Desktop systems.
> 99.0% (two nines) Intermediate business systems
> 99.9% (three nines) Most business data systems and workgroup servers
> 99.99% (four nines) High-end business systems and your friendly
> neighborhood telco
> 99.999% (five nines) Bank Data Centers and Telco Data Centers, some ISPs
> 99.9999% (six nines) Only God and Norad live here.
> 99.99999% (seven nines) Even God doesn't have pockets this deep.

  What's your source for this data?

  -a