Access to the Internic Blocked

Vadim Antonov avg at
Mon Aug 26 21:40:54 UTC 1996

Daniel W. McRobb <dwm at> 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.


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