| I did some of the enhancements. As far as the performance, the throughput is
about the same as the previous version, however the latency was reduced by about
a factor of 3. This was done because of some feedback from University of
Washington during their testing of latencies and RPC's (remote procedure calls).
The ability to disable the Ring Purger algorithm is important, because although
it works great with well-behaving FDDI nodes, it causes bad-behaving nodes to
have problems. Therefore, although Ring Purger is great, some customers need
to turn it off because of other FDDI vendor's problems.
[it might be that just the default for ring purger has changed, I thought it
as always settable].
I can't say for sure whether most customers would notice the latency improvement,
but if I took a guess, I might say no. FDDI can have high latency due to token
rotation, and the controller some latency (it DMA's a minimum of 512
bytes, and that can add significant latency to small packets, such as those used
in RPCs.
Doug Washabaugh
DEFZA Firmware Engineer
|