Why the temptation for dial users to crank back rwin/mtu?

It's always been my belief that the 576 values were generated by hosts
that didn't support Path MTU discovery and wanted to be conservative
and avoid fragmentation. Fair enough..


apparently there's some performance value in this (at least to the


MTU - at least this makes a little bit of sense.. If they're doing
HTTP/1.0 stuff with parallel connections then a smaller MTU is going
to make that parallelization latency much more effective and perceived
performance will go up some.. it doesn't impact full document
retrieval time though (at least not positively!).. are dial links
really lossy enough that chopping the segment size to 1/3 is a big win
in retransmit time or are the win95/98 stacks really braindead enough
that they don't do pmtud so are just trying to dodge fragmentation? I
found it really odd that [7] which I use all the time to track
features in a myriad of shipped OS's actually has a blank entry for
pmtud on both of those (neither yes nor no..)

This is discussed in depth in RFC1191 and W. Richard Stevens' book
"TCP/IP Illustrated Volume 1" (see page 29-31).