Path: utzoo!attcan!uunet!husc6!mailrus!ames!pasteur!ucbvax!rusvx1.rus.uni-stuttgart.dbp.de!nittmann
From: nittmann@rusvx1.rus.uni-stuttgart.dbp.de ("Michael F.H. Nittmann ")
Newsgroups: comp.protocols.tcp-ip
Subject: historical defaults
Message-ID: <111:nittmann@rusvx1.rus.uni-stuttgart.dbp.de>
Date: 27 Jun 88 13:13:10 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 47

Throwing in the following I would like to see if it is worth   
being discussed:
there are two defaults in the telnet standard that are a little bit
hampering on networks since on my opinion they cause lots of
evitable network charge: go ahead and remote echo.

On my own experience most communications in interactive telnet use are
from a workstation to a mainframe computer.
The lines are full duplex as seen from the telnet side. A virtual
circuit of two phone lines or a x.25 virtual circuit look as a 
full duplex line to the telnet.
So: why bother with a go ahead as a default start and not just set
SGA as a default.
The same I think holds for the remote echo. This is a very useful
option when operating over very unreliable lines to very unreliable
hosts. When communicating over a standard network which is reliable
as seen from the bottom side of telnet, and when the tcp/ip used
as a type 4 protocol would take care of resending characters if
they are lost or timed out, so why charge the already overcrowded
network ( re. the breakdowns early in '88) with those single
character echo packets. 
I would guess that nowadays - in 88, not in times on NCP-->TCP
transition - most communications could easily be done with SGA
and local echo. Seen from the mainframe pespective I personnally 
judge it a gigantesque waste of resources to let a multi user
mainframe echo single characters - mainframes may of course
switch that off by negotiating, as is done with SGA. The problem I
see in my experience is that some implementations heavily rely on the 
defaults. When confronted with a non default negotiation at 
communication start some implementations don't work 
correctly. They either insist negotiating their default or
just hang waiting for a GA.
By switching the defaults - SGA and local echo - I think 
we could avoid network charge - two defaults together never
would negotiate e.g. the echo since there is no reson so
they will send those silly 1 character packets.
On the other hand implementors would perhaps be oriented
to the more useful modes as is SGA. Or is there somebody
who really knows he needs the GA any more?

Perhaps this will result in a level 3 or level 4 discussion
opposed to the link level discussion on connectors.(this is OSI
terminology).
                    
And as usual: these are my personal views.

Michael F.H.Nittmann