Re: iSCSI: 12-97 Bit Rule

[Luben Tuikov <luben@splentec.com>]

Bill Studenmund wrote:
> 
> However, the IETF uses this bit numbering scheme in ALL of its documents.
> It is consistent in its bit numbering. Thus if I read an IETF document, I
> prepare my mind for IETF bit numbering.

Wow!
 
> Note that the IETF is not the only group to use this bit numbering. As I
> understand it the Mainframe folks use this bit numbering. Also, the
> documentation I have on PowerPC chips all uses this bit numbering, so it's
> not something the IETF made up.

Wow -- so you've just discovered that it is just a convention --
good for you.
 
> Well, two thoughts come to mind:
> 
> 1) For me, no explanation of how to perform this CRC calculation will make
> sense if it dives into the space of abstract bit streams and such. My mind
> works much better with code snippets.

Aaaah, here is the key!

And my mind works better when I see more abstract ideas,
just because the implementation/bit order/byte order doesn't matter.

> 2) I expect the Linux community will start by looking at the
> implementations out there. The UNH implementation has CRC32C code in it.
> That code, AFAICT, is correct.

You forget that there are incrediby smart ppl there, that will
most likely NOT look, since they've done it before, long ago,
in a galaxy far, far away... but I digress.
 
> I'm sorry, that came out wrong. If your main point was that your proposed
> text is independent of bit numbering, then the way you were discussing
> Julian's use of the bit numbering which is consistent with the rest of the
> document didn't help. At least not for me.

Well, what can I say? (red star for Bill, black dot for Luben)

-- 
Luben