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From: timm@Sed.Novell.COM (Tim Myers)
Newsgroups: comp.sys.novell
Subject: Re: IPX corruption possible across routers
Message-ID: <1991Jun7.185359.659@npd.Novell.COM>
Date: 7 Jun 91 18:53:59 GMT
Sender: news@npd.Novell.COM
Organization: Novell, Inc.
Lines: 35

In article <1056@rsp.UUCP> tom@rsp.UUCP (Thomas Ruf) writes:
> I'd rather have my CPU spent some cycles checking end-to-end checksums
> as in tcp/ip than blindly trust all those fancy boxes moving bits over
> the ocean. 

Did the original post from NASA mention anything about moving bits over
the ocean?

The implementors of IPX thought differently about how CPU cycles should
be spent--checksums are ignored. The designers of AppleTalk also thought differently--checksums are optional. This different thinking about what
is best for specific applications is what has led to a polyglot protocol
world. 

Yes, there is a place for end-to-end checksums, but I don't need it on
my LAN. If you want to send bits over the ocean you have my blessing to
use TCP/IP on your WAN. If you want to send bits to the other end of the
solar system you will need yet another protocol because your precious
checksums will not deliver the goods.

> Thomas , inventor of IPX over UDP/IP, of course with NO WAY of
> turning off UDP checksums.

Then you especially should understand the issues, both for and 
against the use of checksums, cyclic redundancy checks, and error 
correction codes on a LAN, MAN, or WAN!


++Tim

Are we about finished with this subject?
===========================================
Tim Myers
Senior Software Consultant
Novell, Inc.
"Macintosh: the only GUI that doesn't SUCK."