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Re: generators, etc....
In message <Pine.LNX.3.95.961013231754.15595Aemail@example.com>, Nathan Strat ton writes: >> We all scream for fixes when these outages occur. How much are we >> (and our customers) willing to pay for them? > >Look, I don't think people are asking for 100% uptime, but 99.999 is a >valid goal, and can be reached. I had to learn that hard way that a >generator at every pop was something was saved you money. Sorry wrong answer. Five 9s is less than 6 minutes of downtime/year. A large amount of the telco gear is only rated at six nines. (Six nines is less than 1 minute of downtime/year.) Thats not even getting into the issue of downtime v. availability. With the delays in BGP processing commonly seen today, (on the order of 15 minutes), one prefix flapping would put that prefix at less than four nines (11 minutes). Three nines, (just under two hours), would be a good goal for planned availability. Then of course, there is the issue of maintence. I understand telephone switch software designers have the problem of all switch upgrades have to be done with the switch running. There is a whole programming group at some companies that searchs for extra bits in structures to add new features, because they can't reboot the things to change the size of data strucutres... That just ain't gonna happen, when your favorite router vendor's best guess for fixing some problems is to reload the router.... (or you have to install new firmware, and do a reload to get it going...) Not all routers may be this way, but for any deployed networks today, three nines is going to be an upper limit. --- Jeremy Porter, Freeside Communications, Inc. firstname.lastname@example.org PO BOX 80315 Austin, Tx 78708 | 1-800-968-8750 | 512-458-9810 http://www.fc.net - - - - - - - - - - - - - - - - -