From my understanding there is a 99.97% up time value that most companies try
and match. Is this a hard and fast rule or is this a value that we all try
and emulate as best as we can? Do I have the value incorrect? Is it higher
or lower? I had always thought that it was 99.97% but have not found
anywhere to reference that figure, it was just via talking with others and
checking available uptime statistics. My understanding also takes into
account that it does not include controlled downtime due to any maintenances.
Any thoughts?
Kim
From my understanding there is a 99.97% up time value that most companies try
and match. Is this a hard and fast rule or is this a value that we all try
and emulate as best as we can? Do I have the value incorrect? Is it higher
or lower? I had always thought that it was 99.97% but have not found
anywhere to reference that figure, it was just via talking with others and
checking available uptime statistics. My understanding also takes into
account that it does not include controlled downtime due to any maintenances.
Any thoughts?
From my point of view, and the clients I deal with, like to keep there core network and systems at 5 nines (99.999%). But that is the regulated lottery world, and we can be fined heavily if we don't meet that level of uptime.
Oh and scheduled outages aren't included, but everything is redundant so we just work on one then the other so there is network wide outage, just a lack of redundancy for x number of minutes.
-Vince
There is no industry technical standard. Different Internet service
providers advertise a wide-variety of numbers set by their marketing
departments. Depending on the customer and provider, you may negogiate
other values more suitable for your budget and requirements. It is
common for ISPs to advertise 100% uptime guarantee*. That asterisk
is the critical piece of information. Most service providers loath
to call anything an "outage" no matter how bad the service gets. Just
what is emergency scheduled maintenance or routine emergency operation?
My personal favorite example along this line came from Verio, who tried to
claim that they shouldn't have to pay an SLA credit for a 24 hour outage
because, even though their monitoring clearly showed that their router
would route for 30 seconds and then not route for 30 seconds, that was a
"bunch of 30 second outages" and not a 24 hour outage.
Just remember, it's not an outage, it's an (quoting AboveNet here)
"unscheduled network event". 