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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Access to the Internic Blocked
Daniel W. McRobb <dwm@ans.net> wrote: > >1-2 million is not much. Even in the NSFNET days, I worked w/ > >5-million-cell net matrices. All it takes is memory and some CPU. > > 1-2 _simultaneoulsy_, not over period of time. The 1-hr matrix > would be two orders of magnitude bigger. >A typical 1 hour matrix is considerably smaller. Even a core router >who carries 40,000 routes will not see anywhere near 40,000 * 40,000 >cells in a one hour period, or even 2 million cells. Not in my >experience. Even the NAP and MAE routers where I've collected this data >have seen net matrices only on the order of (10^3) to (10^5) for a one >hour period. That's _host address_ matrix, not network address matrix. It is at least three orders of magnitude bigger. Another datum -- the hot spot on route cache on ICM's routers from hell is about 40% on networks addresses. >The number of cell entries is not equal to the number of routes squared. >It doesn't happen. No, nobody said that. That's why my figures are in 100M range, not 2000000 bil which is the size of "full host matrix". >Even if your router is expiring 20,000 flows per second, >it only comes out to about 667 packets per second to the workstation, >which is pretty low even for older workstations with fairly weak CPUs by >modern standards. An Alpha can handle it w/o even breaking a sweat. 20k flows per second? You must be kidding. The average flow length (as derived from Sean's stats) is 20 packets. I.e. 20 kfps is what you get from a single OC-3 working at the wire speed. --vadim - - - - - - - - - - - - - - - - -
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