Hal Murray <[email protected]> wrote: > > The 10/100/1000 on Ethernet speed refers to net data rate. The actual bit > rate on the wire is faster to compensate for things like 8B/10B encoding. For > example, 100 megabit Ethernet is actually 125 on the wire if you look at it > with a scope.
The symbol rate for gigabit is also 125MHz because it needs to fit in the same bandwidth for compatibility with 100meg cabling and emissions standards. It gets the higher data rate by using all the pairs bidirectionally and by using more volage levels. All-pairs-bidi is why crossover cables aren't a thing any more. (Except literalljust as I was writing that sentence a colleague came into the office looking for a 10meg crossover cable!) Gigabit ethernet is pretty neat. Tony. -- f.anthony.n.finch <[email protected]> http://dotat.at/ Humber, Thames, Dover: Westerly, becoming cyclonic, 4 to 6, occasionally 7 later. Slight or moderate, occasionally rough. Showers, rain later. Good, occasionally poor later. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
