Re: Question on PE Checksum

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On Thursday 21 July 2005 09:21, Michael Tuexen wrote:
> Hi Walter,
>
> I have looked into efficient ways of implementing the Internet checksum
> and figured
> out that you need 32 bit arithmetic to calculate the 16 bit checksum.
> When using
> a '32 bit Internet checksum' this would require support for 64 bit
> integers.

Yes.

> I do think that we should not require that.

But is this really relevant on today's computers and compilers? Working with 
64-bit integers ("long long" datatype) is for example part of the ANSI-C 
standard since ANSI C99 (http://www.nirvani.net/docs/ansi_c.pdf). This 
standard is six years old.

I think the effort to use the 32-bit sum is not significantly higher than to 
use the 16-bit sum; but the probability that handlespace inconsistencies are 
detected is.


Best regards
- -- 
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 Dipl.-Inform. Thomas Dreibholz

 University of Essen,                            Room ES210
 Inst. for Experimental Mathematics              Ellernstraße 29
 Computer Networking Technology Group            D-45326 Essen/Germany
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 E-Mail:     [email protected]
 Homepage:   http://www.exp-math.uni-essen.de/~dreibh
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