The Myth of Five 9's Reliability (fwd)

Thu Apr 25 20:39:55 UTC 2002

Doh. This should have read "Your service" not "Your server".

-----Original Message-----
From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu]On Behalf Of
Deepak Jain
Sent: Thursday, April 25, 2002 4:26 PM
To: Mathew Lodge; Art Houle; Pete Kruckenberg
Cc: nanog at merit.edu
Subject: RE: The Myth of Five 9's Reliability (fwd)

[stuff missing]
When applied randomly to the Internet, I suppose that means if you can dial
into a RAS and establish a PPP/IPCP session, but the RAS' connection to the
Internet is down, then the service is up :-)

[stuff missing]

I seem to remember a large internet provider's service contract reading
something to the effect of. "Your server is considered down if customer
router cannot pass packets [or ping] with service provider's immediate
upstream router." This is a functional description of the above for
dedicated lines, as customer aggregation routers never talked to the
internet, so if there was a problem at a transit router you weren't getting
anywhere.

A modern contract I saw recently defined "up" for colocation purposes as
"the customer's assigned gigabit port is available." Though available was
not a defined term, one could not easily apply that to a ports' willingness
to pass packets. One could say a congested port was not available though, I
guess.

Deepak Jain
AiNET