Path: utzoo!utgpu!watserv1!watmath!att!linac!uwm.edu!cs.utexas.edu!sun-barr!lll-winken!gauss.llnl.gov!casey
From: casey@gauss.llnl.gov (Casey Leedom)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Want 8-bit/256 character clean TELNET session -- is it possible?
Message-ID: <89746@lll-winken.LLNL.GOV>
Date: 18 Jan 91 18:43:38 GMT
References: <89689@lll-winken.LLNL.GOV>
Sender: usenet@lll-winken.LLNL.GOV
Reply-To: casey@gauss.llnl.gov (Casey Leedom)
Organization: Lawrence Livermore National Laboratory
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  Well, from cruising through the various TELNET RFCs, it look like it's
impossible to establish an 8-bit/256 character clean *and* efficient
channel.  Moreover, it appears to be impossible to do this automatically
from the server.

  Even if you enable TELNET BINARY mode and set tesc to UNDEFINED (which
I only presume will work, not having had a chance to test it), the client
(in the Annex) is forced to constantly scan for IAC (the TELNET command
escape) in both the inbound and outbout data streams.  I suppose that
this isn't much load on the Annex, but it sure would be nice just to be
able to say ``open host port'' from the Annex CLI (Command Line
Interface) and have the Annex open a TCP connection to the indicated host
and port and then step out of the way.

  More seriously, it doesn't appear to be possible for the server to
negotiate away the client ESCAPE processing; primarily because ESCAPE
processing isn't part of the TELNET protocol.  ESCAPE processing is a
client function.  It sounds to me as if an intelligent client should
automatically turn off ESCAPE processing if a server requests BINARY
mode, but, unfortunately, that's not even recommended by the standards as
far as I can see.

  (sigh) I think I'm screwed.

Casey