Thus spake "Greene, Patrick" <PJGreene@infotechent.net>
> The 7600 is an 6500 in all respects. Here are the some of the gotchas.
> The key to the 7600/6500 is the capability to insert a couple switch
> fabric cards and use OSM's for the full 256GB backplane capability for
> full wirespeed cruising. Here's the gotcha, if you put any non OSM
> cards into the chasis all cards, EVEN OSM's, will step down to the
> slowest cards backplane speed.
The Cat6k forwarding system is much more complicated than that.
Distributed Forwarding cards (68xx) use only the xbar, so they do not care
about the presence of non-fabric cards.
Fabric-enabled cards (65xx, OSMs) use the bus in Compact Mode (30Mpps) or
Truncated Mode (15Mpps) depending on the presence of non-fabric cards. In
either case, only the headers are sent on the bus, so they don't consume
much bw.
Non-fabric cards (61xx-64xx) use the bus in Full Mode (~15Mpps) no matter
what. They send entire frames, so performance is bw-constrained.
S
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