On Jul 10, 10:44, John Hawkinson <jhawk@bbnplanet.com> 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: bilse@EU.net