Daniel W. McRobb <dwm(a)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
