On Fri, Dec 13, 2013 at 1:42 PM, Edward Ned Harvey (blu) <b...@nedharvey.com> wrote: >> From: discuss-bounces+blu=nedharvey....@blu.org [mailto:discuss- >> bounces+blu=nedharvey....@blu.org] On Behalf Of Kent Borg
>> Something else I long ago observed: Because ethernet degrades gracefully it >> always operates degraded. > > Ethernet does NOT degrade gracefully. A graceful degradation would be: You > have 11 machines on a network together. 1 is a server, and 10 are clients. > All 10 clients hammer the server, and all 10 of them each get 10% of the > bandwidth that the server can sustain. This is the behavior of other network > switching topologies (in particular IB and FC) but it is not the behavior of > Ethernet. Because Ethernet is asynchronous, buffered, store and forward, > with flow control packets and collisions... Sure, the most intelligent > switches can eliminate collisions, but flow control is still necessary, > buffering is still necessary... You have network overhead, and congestion > leads to degradation of efficiency. Each of the 10 clients might be getting > 5% of the bandwidth, which is an ungraceful degradation. Ed: Can you define what you mean by "collision" in the context of an Ethernet switch where twisted pair wiring is being used? (i.e. any of the commonly used *BaseT wiring systems) The definition I use makes collisions impossible and therefore irrelevant to virtually any discussion of Ethernet taking place in this century. Thanks, Bill Bogstad _______________________________________________ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
