dlb25@chemabs.UUCP (Dave Besselievre) (01/23/91)
Chemical Abstracts Service is seeing the following problem on our DEC/SUN
network. When using rsh/rlogin on an idle systems (local and remote) we see
keystrokes being broken into single character Ethernet packets when being sent
to the remote system. This is ok when the user is entering text, but during
cursor movement, multi-character sequences are generated for each keystroke
the users types. The sending of these packets containing a single character,
very quickly causes the packets to backup, and more they one keystroke is then
packaged into a Ethernet packet. This leads to the cursor movements being
jerky. (ie. the cursor jumps 3 to 5 character locations at a time. This
behavior is seen by the user as if the remote system is slow or not responding
correctly. As the system load increases on the remote system this behavior
becomes worse.
Now if the user uses "telnet" to connect to the remote system, this behavior
does not occur. If you look at the Ethernet packets being sent we see that
multi-character keystrokes are being sent as one Ethernet packets.
And the system never gets behind due to Ethernet packet traffic.
The problem is that rsh/rlogin provides features that are not available under
telnet (ie, automatic login and remote execution of programs). Is there any
way to cause the rsh/rlogin process to package the multi-character keystrokes
as one Ethernet packet as the telnet program does.
Could this problem be caused by any OS environmental problem?
Please send any suggestion on how to correct this to:
dlb25@chemabs!osu-cics
dlb25%cas.BITNET@CUNYVM.CUNY.Edu
dlb25%CAS@pucc.PRINCETON.EDU
David Besselievre
Chemical Abstracts Service
614-447-3600 X3545
Testing environment
~~~~~~~~~~~~~~~~~~
CAS has 12 VAX 785 running Ultrix 3.1 and one VAX 785 running Ultrix 4.0.
There are also 3 VAX 8820 running ULTRIX 4.0 We have 370+ Sparc 1+ WS on the
network running SUN OS 4.1 configured into tree Subnet. The VAXS are evenly
distributed between the three subnets.
We have found that the problem occurs when the remote system is on local or
remote subnet; remote system is a VAX 785, 8820 or SUN WS; and under SUN OS,
Ultrix 3.1 or Ultrix 4.0. This problem occurs under both programs telnet and
rsh/rlogin when they are executed from a sun window environment, but the
telnet program still performs better than the rsh/rlogin program does when
outside the windowing environment. When execution is between VAXs, there is
not problem with the telnet keystroke response. And the SUN users do not feel
that the telnet responsiveness is poor in the SUN Windows environment. But
they find the rsh/login very objectionable, in both the Sun windows and
VAXs environments.
In a moderately busy remote system we are seeing as much as three to four
words being skipped in cursor jumps when the user performs a smooth cursor
scrolling to the right (ie. users hold down right arrow key), under rsh/rlogin.
Where the same document and operation in a telnet connection, provides smooth
scrolling.
_________________________________________________
| ____ ___ ____| |
| / \ __ \ / | David L. Besselievre |
|| / |\ ___| Chemical Abstracts Service |
|| | | | Columbus, OH 43210 |
|| | | | |
| \ ____ \____/|\____| osu-cis!chemabs!dlb25 |
| | dlb25@cas.bitnet |
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