[e2e] end2end vs smtp

[Vernon Schryver]

> From: Tim Moors <tim_moors at yahoo.com>

> I think that their point stems from a common
> misconception that the reliability of TCP is perfect -
> there is not even the possibility of an errored
> segment evading detection by TCP's checksum.

Only graduates of the Wishful Thinking School of Design think that
the TCP checksum is perfect, or like such checksumming schemes as
that proposed SMTP think with its recomputing at every hop exactly
where the corruption almost certain to happen.

>                                               This
> misconception probably follows the juxtaposition of
> "reliable" TCP vs "unreliable" UDP.  It would be nice
> if the true endpoints could check integrity (as this
> draft proposes)

As the IESG points out, there are other, already standardized mechanisms
that can actually catch the vast majority of real SMTP corruption.

>                 and TCP's checksum could be disabled
> for cases such as this where it is redundant and may
> interfere with performance.

It would be really swell if we could stop hearing that old stuff.  It's
10 years past time to be gentle with those who try to resurrect it.
It's at least 10 years since it was shown in common commercial systems
that the TCP checksum is can be free.  It has been more than 10 years
since people started talking about the supposed redundancy of the TCP
checksum, and there are still no known scenarios that do not have real
life examples of corruption detected by the TCP checksum that would
otherwise have been undetected.

In other words, please type `netstat -s | grep sum` 100 times in penance.


Vernon Schryver    vjs at rhyolite.com