Columbia Kermit/kermit.zip/newsgroups/misc.19960425-19960715/[e-mail] _Fri Jul 5 04:03:17 1996.msg

Internet Message Format | 2020-01-01 | 4KB

Return-Path: [e-mail]
Received: from apakabar.cc.columbia.edu (newsmaster.cc.columbia.edu [128.59.35.30]) by watsun.cc.columbia.edu (8.7.5/8.7.3) with ESMTP id EAA01030 for <[e-mail]>; Fri, 5 Jul 1996 04:03:16 -0400 (EDT)
Received: (from news@localhost) by apakabar.cc.columbia.edu (8.7.5/8.7.3) id DAA24490 for kermit.misc@watsun; Fri, 5 Jul 1996 03:59:16 -0400 (EDT)
From: [e-mail] (Joe Doupnik)
Newsgroups: comp.protocols.kermit.misc
Subject: Re: Disable local echo in Telnet
Message-ID: <[e-mail]>
Date: 4 Jul 96 19:38:57 MDT
References: <[e-mail]> <[e-mail]> <[e-mail]>
Organization: Utah State University
Lines: 52
Path: news.columbia.edu!panix!bloom-beacon.mit.edu!gatech!news.mindspring.com!cssun.mathcs.emory.edu!swrinde!howland.reston.ans.net!newsfeed.internetmci.com!news.internetMCI.com!pull-feed.internetmci.com!news.provo.novell.com!news.cs.utah.edu!cc.usu.edu!jrd

In article <[e-mail]>, Chancellors <[e-mail]> writes:
> Joe Doupnik wrote:
>>
>> In article <[e-mail]>, Chancellors <[e-mail]> writes:
>> > We are running MS-DOS Kermit 3.14 on a networked PC and C-Kermit 5A(190)
>> > on a DEC Alpha box.I need to disable local echo within a Telnet session.
>> > On the DEC Alpha the 'set telnet echo remote' command works fine but
>> > there appears to be no equivalent in MS-DOS Kermit.If I use the command
>> > 'set local-echo off' the 'show communication' command shows echo is off
>> > but as soon as I start a Telnet session echo is swithed back on.
>> >
>> > Any ideas?
>> >
>> > Dave Stephens - [e-mail]
>> -------------
>>         Local/remote echoing over a Telnet connection is a Telnet Option
>> negotiation result. Prior to negotiation echoing is local. If you Telnet
>> to a non-Telnet port no negotiations occur and you are left with local
>> echoing. Telnet is TCP port 23, the default unless you state otherwise.
>>         Perhaps you can help us with a few more details on that connection
>> process. As an aide you can say SET TCP DEBUG ON to see the Telnet Options
>> be negotiated when a session starts.
>>         Joe D.
>
> What we have is a viewdata service modified to enable it to receive
> incoming telnet connections which it listens for on its own port number.
> At present there is no negotiation on connection.When using kermit on the
> alpha to connect, all we need is to set telnet echo remote to give us
> the required behavior.We would like MS-DOS Kermit to behave in the same
> manner.
>
> Dave Stephens.
-------------
    Since MS-DOS Kermit performs no Telnet Option initial offers when
going to a TCP port other than 23 (Telnet) then the default Telnet conditions
apply (meaning echo locally etc). They are established as a session commences.
Once the session has begun you can give the command SET LOCAL-ECHO OFF at the
Kermit prompt and that will let the remote host provide any data to the Kermit
screen.
    Alternatively, a cleaner long term solution would be for your host
end to perform Telnet Options negotiations to establish the desired behavior.
The pair of Options necessary are SGA (Suppress Go Aheads) and ECHO, or
even mimimally just the ECHO Option. The latter would look like this:
    host commands DONT ECHO    (so client does not echo back host bytes)
    client responds WONT ECHO  (client agrees to not echo back)
    host offers WILL ECHO      (host offers to echo back to client)
    client responds DO ECHO    (client agrees to that arrangement)

You can see that without negotiation there is the chance that the client side
will bounce host bytes back to the host, and I'm sure your application would
not appreciate that. And it means one less Tech Support item for everyone.
    Joe D.