65-node simple mesh test (and counting... ;-)

Marcus Leech mleech at nortel.com
Fri May 9 10:57:24 EDT 2008

The following graph is the cumulative distribution function. It shows
that, on average, each XO has received about 95% of the profiles of the
rest of the nodes within just 20 seconds. This performance boost is due
to the fact that each XO queried for its profile, responds by
broadcasting the profile, instead of unicasting it to the requester. As
a result, the other nodes receive the profile too and the next node is
queried, yielding a linear cost, instead of a quadratic one.

I'd be *very* interested to compare the distribution on a wired network.
It seems to me that given
  the broadcast model, everybody should see everybody else in much
shorter time than the 55 seconds
  shown in the outlying cluster on that graph.  For example, if you
plugged all of those 65 Xos
  into a wired network (100Mbits/sec), then if the "convergence time"
shrinks by roughly a factor
  of two (100Mbits vs 54Mbits), then we know that the wireless
networking stuff on the XO is
  basically functioning correctly.  If, however, the convergence time
becomes *very* much shorter
  on a wired network (let's say by a factor of 5 or more), then
something is likely wrong with
  the 802.11 goop on the XO.

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