Jeff, uncharacteristically, misspeaks when he says:

> So, if you can type faster than your round trip time, it will reduce
>  the packet count by default if Nagle-type queueing is supported.
>
>  This applies only to standard telnet connections, however.  Connections
>  using "local-echo" (QCTerm's "advanced" telnet) already avoid the single
>  character packets.

"Advanced telnet" is not a line mode-oriented transmission, such as occurs in
NS/VT, where a whole buffer of characters is transmitted only after a CR is
typed (or a specific number of characters has been entered into the buffer,
or a timeout has occurred). "Advanced telnet" continues to transmit one (or a
few) characters per packet, just like standard telnet. It's just that
"advanced telnet" turns off the host's echo, so the data transmission path is
only one way for the typed characters. No single-character packets are echoed
back from the host the terminal.

Rather, the advantage of "advanced telnet" is the great psychological benefit
of having the characters appear on the terminal's screen the instant they're
typed rather than having to wait for the round-trip echo from some very
distant host over the internet.

While, as has been discussed, these single-character packets seem to weigh
heavily against telnet in comparison to NS/VT in regards to efficiency, when
truth is told, they hardly matter. Communications with a remote host is
virtually always extremely asymmetric. You type a little; the host dumps a
lot of text back at you. You can see that in every

    LIST @,@,2

...command. You typed 11 characters. The HP3000 returns 30,000.

While there may be some little difference in how NS/VT vs. telnet packets are
formatted as they are being sent from the HP3000 to the terrminal, ultimately
all of the data arrives at the terminal. To every practical measure, the
efficiencies are identical whether you're using telnet or NS/VT in regards to
the data being transmitted to the client terminal from the host. This is
heavy-duty flow path.

Similarly, if you're using block mode screens, there is again no difference
between NS/VT and telnet. Nothing is being transmitted to the host as you
fill in the block mode form until you press the ENTER key, and then,
everything is transmitted as one buffer, generally all within one packet.

The bottom line of all of this is: there really is no difference between
NS/VT and telnet efficiencies if you aggregate all flows between a host and
its client terminal, or at least not enough to write home to mother about.

Secondly, the advantage of "advanced telnet" doesn't really lie in increased
efficient use of bandwidth (although there is some). Rather, its advantage
lies solely in the look and feel of the typing process, making your typed
characters appear instantly on the screen and often cutting the host's
response times in half.

Wirt Atmar

* To join/leave the list, search archives, change list settings, *
* etc., please visit http://raven.utc.edu/archives/hp3000-l.html *