[AG-TECH] Unicast-Multicast bridges?

Stuart Levy slevy at ncsa.uiuc.edu
Mon Jan 21 21:05:57 CST 2002


I have a simple one at

   http://niri.ncsa.uiuc.edu/tools/udpbridge.tar.gz

You specify the port-pairs that it should forward on.
And there's no security (though there's a code stub for
an access list).  Anyone who sends a unicast packet, at least
one per two minutes, to the bridge on either port of a port-pair
will get all traffic on that port-pair.

One bridge can forward several port-pairs.  E.g.

   udpbridge -p 8666  224.3.175.111/8666/24    -p 6822  224.117.3.51/6822/32

The "-p NNNN" listens on that odd-even unicast port pair, and
mcastaddr/port/ttl does likewise for that multicast address/port-pair.

It would need to run on a machine that had multicast access;
is it true that you don't (or won't) have that anywhere in Boeing?

It'd also need to run on a machine that wasn't using any of those
ports for other applications, so it couldn't be on an AG machine itself.

And, I've never used this in the high-traffic AG environment;
it doesn't seem to take any noticeable CPU time when forwarding 100-odd
packets per second (~1% CPU at 50 pps input, 150 output), but
your mileage may well vary...

    Stuart



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