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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: AGIS Route Flaps Interrupting its Peering?
> This actually works reasonably well as long as you don't try to cram 20Mbps > of data through it in aggregate. > > The problem that one particular provider had was trying to do this > full-mesh AND ignoring the fact that Ethernet isn't really 10Mbps; its > more like 5-6Mbps when you take the duplexing issues into account. Now add > the collision domain problems to this (you really don't have a 3000-mile > collision domain; its "faked" in the translation) and limited buffering and > you can see where some problems show up really quickly, especially when you > sell resale T1s to people and don't upgrade the backbone to meet the > increasing sales of circuits...... > > If you only mesh the places you need to talk to from one point to another > and use a better exit technology at exchange points (allowing an aggregate > data rate > 10mbps) it works quite well. Try to go "cheap" and use the AUI > interface everywhere and you get a different result. And I know a provider that despite realistic expectations of the technology, still experience serious problems with everything that Sean mentioned. 50% of all problems were caused by inadequate buffering, and the other 50% were caused by PVC's either dissappearing, or being re-routed around the wrong end of the country. (Gee, 250ms from San Francisco to San Jose...it's taking the east coast route again...) > > -- mixed-media bridging (NetEdges, FDDI/Ethernet bridges) > > Netedge <> Ethernet works quite well (far better than RETIX<>Ethernet.) No argument on the Retix's. > Netedge<>FDDI has been reported to have the problems you listed, and more. not quite there yet, no. > > Finally, why is it that most vendors never test their products in > > a serious battlefield environment like an ISP of size medium to huge? > > These places tend to be excellent worst-case testing grounds. > > That's a good question... What are you talking about? They do a series of stress tests designed to push the equipment to it's utmost capabilities in their state-of-the-art ...laboratory. heh. Dave -- Dave Siegel Sr. Network Engineer, RTD Systems & Networking (520)623-9663 x130 Network Consultant -- Regional/National NSPs [email protected] User Tracking & Acctg -- "Written by an ISP, http://www.rtd.com/~dsiegel/ for an ISP." - - - - - - - - - - - - - - - - -
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