North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Ping flooding (fwd)
On Jul 10, 10:44, John Hawkinson <[email protected]> wrote: > > Is it just me, or are the ANS commandos after me? > > It's just you, really :-) Good to hear. :-) > This is the short-term, long-term issue. > > If you want to know who you exchange traffic with, who you need to > consider peering with in more places or establishing additional links > to, you need things like AS matrices. We certainly appreciate the > modicum of data we have now, and would be happier with more of it. > > Knowing how hot each of your links is is nice, and may > help you see short-term spikes, but it doesn't help long-term > engineering of your network. Yes, but 'long-term' is one of these things ... You can't really project with any degree of accuracy more than 6-9 months ahead, and our experience indicates that historical data is not all that useful. (Ie, that is the case for us; it may be different for other people.) There aren't any agreed ways of measuring the capacity of networks, but my take on our capacity is that we have 100-150 times more capacity than three years ago. Ie, this is what we can extract from historical data; but there is a limit to how far into the future one can project, using this data, and it certainly isn't three years. > > As noted, busy core routers are ill suited for collecting IP > > accounting. The fact that they may be border routers in BGP terms > > doesn't make them any less core routers from a network perspective. > > So you just have to rig things differently, then. > > This is getting silly :-) It's relatively well-established that if you > want to collect data somewhere, getting it right is going to be hard. > The more you want to collect, the harder it is. Yes, but my point is that bean-counting accuracy, "proof", hard facts, etc isn't particularly important. You want to look at trends for long-term planning, and current measurements to see if you should maybe reroute traffic over alternative connections, sort of "right now". Between those two extremes, a good nose and healthy gut is likely to be more useful than even the most careful analysis of historical data, simply because growth doesn't necessarily follow any particular pattern. > Invariably it's useful to have stats on boxes at the borders of your > network where you peer with other folks, and it's also useful > inside your network. All of these things depend on what you're trying > to engineer for, and almost all of them are useful. Balancing usefulness > versus forwarding path performance is a tricky thing, but one should not > assume it's impossible, and considering the possibilities is far more > than a waste of time. Sure, nobody would disagree with that. -- ------ ___ --- Per G. Bilse, Mgr Network Operations Ctr ----- / / / __ ___ _/_ ---- EUnet Communications Services B.V. ---- /--- / / / / /__/ / ----- Singel 540, 1017 AZ Amsterdam, NL --- /___ /__/ / / /__ / ------ tel: +31 20 6233803, fax: +31 20 6224657 --- ------- 24hr emergency number: +31 20 421 0865 --- Connecting Europe since 1982 --- http://www.EU.net e-mail: [email protected] - - - - - - - - - - - - - - - - -
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