TCP chokes between Ultrix 4 and 3.1c systems

[Rice Don D]

Yet another amusing feature.  I think this may have come up quite some time
back.  When I use ftp, telnet, or even mail to a DS3100 running Ultrix 3.1c
from my DS5000 running Ultrix 4.0, the connection hangs whenever 512 or more
bytes are sent from a single operation (e.g., mail messages, ftp files,
or commands in telnet).  The same thing happens when the folks on the other
end try to talk to me.  Neither of us have any problems talking to non-Ultrix
systems, and I can talk to other Ultrix 4.0 systems just fine.

No doubt the answer is to upgrade the other guys to 4.0, but they don't want
to do anything that radical now that school is in session.  Is there some
parameter to tweak or some patch they can request to fix the problem?

Thanks,
Don Rice                                  Internet: fnddr at acad3.fai.alaska.edu
Geophysical Institute                     E-mail:   fnddr at alaska.bitnet
University of Alaska                      Phone:    (907) 474-7569
Fairbanks, AK 99775                       Loran:    64.86N 212.16E

PS: I tried to send a reply to avolio at decuac.dec.com, but mail says it can't
connect to the remote host.