John Korb writes:
> The systems I usually end up telneting into
> are running 5.5 PP4, but there are also at least two 56Kb "trunk" lines
> between the internet and the HP 3000s, so part of the problem I see is
> caused by a lack of bandwidth. From home, on a good day I see 200-370 ms
> ping times. On a typical day the ping time is around 500 to 600 ms. A bad
> day is when the ping time exceeds 2500 ms. Telnet seems to start to fall
> apart when the ping time exceeds 700 ms. Once the ping time exceeds about
> 1200 ms, or if there is any packet loss, telnet becomes unusable because of
> dropped characters (input) or significant data loss (dropped lines or
> blocks of lines on output). For whatever reason, on 5.5 PP4 NS-VT seems to
> operate just fine when the conditions make telnet impossible to use.
Your comments, John, are exactly correct. The problem is bandwidth. The
current version of telnet begins to fall apart when ping times get to about
700-800 ms. But, thankfully, HP (in the form of Jeff Bandle) has fixed the
problem. In part, that's what I meant by the new high-resilency version of
telnet that will appear in MPE/iX 6.x, with understanding that the "x" being a
little indeterminate.
But let me not mislead you. To make telnet as pleasant to use as I suggested,
the communication mode has to be half-duplex (what we call "Advanced") in
QCTerm. Reflection doesn't support this mode yet (if ever) -- and neither does
the DTC-based Telnet Access Card (and, of course, now never will).
I realize that you may be completely committed to using Reflection for other
reasons, such as scripting, but just for information's sake, download a copy
of QCTerm and try out the Advanced Telnet mode even with the version of HP3000
telnet you have now. You should see a dramatic improvement in psychological
performance, essentially equivalent to NS/VT.
There are a few known problems with telnet on the HP3000 and I written a brief
discussion of them at the bottom of the page that occurs at:
http://aics-research.com/qcterm/connect.html
but they aren't that many -- and "advanced" half-duplex telnet does work
nicely with the PP4 version of host-based telnet. Essentially all of these
problems are now gone, it's just that you don't have the code yet.
Wirt Atmar
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