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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: dual router vs. single "reliable" router
The report seermed to like the boxes from the companies that Alcatel bought. On this side of the pond they did not get alot of traction. >From my experience with a "large" Cisco network besides the normal too many fingers on the CLI to the router there were about one to two hardware failures a week on the big "C" devices. Most of these were interface cards but some were control cards on switches. As long as you did not overrun the 12xxx series with too many BGP updates per unit of time they as a box were stable. To calculate "99.99" per cent uptime you - Define scheduled down time as any maintanance that can be done after giving the worldwide network at least five minutes notice of major network outages ... Define the device to be up as long as you can secure telnet into the box and get a command prompt - Ignore BGP, routing or forwarding tables or any other routing issues because "Up-Time" means the box is up not that it is doing any usefull work ... And finally go back to a "real person" deterministic protocol like "ATM" with PNNI and UNI so you "know" when the network is down and do not have to guess ... My layer two network ran for two years with no hardware or routing issues ... The other minor technical issue is that say you can calculate uptime on a "router" how do you calculate up time on the network? ... Since just because one router is down the "network" is still up so individual up-time for a router in an IP network may only affect SLAs for customer directly attached to it. John (It Suites Dennis's Needs) Lee David Barak wrote: Okay, I'll bite... the mentioned file, http://www.nspllc.com/New%20Pages/Reliable%20IP%20Nodes.pdf seems to be fluff to me. There are many assumptions and statements about reliability, but the methodology of how the numbers were reached is not present. If one assumes that one has a router which fails very rarely, this would dramatically affect network design. However, this is an assumption, not a conclusion. The assumption of the paper is that the Alcatel box has ultra-low failure rates, while the Juniper and Cisco boxen have relatively high failure rates. Personally, before I let something like this influence my buying/design decisions, I'd want to see some serious raw data... ===== David Barak -fully RFC 1925 compliant- __________________________________________________ Do you Yahoo!? Yahoo! Tax Center - File online, calculators, forms, and more http://tax.yahoo.com
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