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Re: Big B, little b





Some history might help to resolve this thread.
The '8B/10B' acronym demonstrably does not trace back to IBM. We simply
adopted  the code classification scheme mX/nY which had been widely used in
technical literature long before the Fibre Channel code was developed. X
and Y stand for the number of transmission levels (Binary for two, Ternary
for three, etc.), m and n indicated the number of symbols at the respective
levels. So 8B/10B implies that 8 binary symbols are translated into 10
binary symbols. Codes of the class 4B/3T translate 4 binary symbols into
three ternary symbols. This notation is used in major textbooks and IEEE
publications as any search for the terms quickly reveals. In a context
where nothing but binary systems are discussed, one might want to simply
drop the big B and shorten the acronym to 8/10. Both 8/10 and 8B/10B are
deficient insofar as they are not referencing a specific 8B/10B code of
which there are many. How about FC8/10 as abbreviation for Fibre Channel
8B/10B code?

Albert Widmer, IBM T.J. Watson Research Center. EMAIL: widmer @us.ibm.com




Mark B. Ritter