Path: utzoo!attcan!uunet!husc6!mailrus!ames!pasteur!ucbvax!PARK-STREET.BBN.COM!brescia
From: brescia@PARK-STREET.BBN.COM (Mike Brescia)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: telnet...
Message-ID: <8807081317.AA15554@ucbvax.Berkeley.EDU>
Date: 7 Jul 88 22:20:22 GMT
References: <8807061753.AA07059@TOTO.MIT.EDU>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 22


     A "DON'T TELNET ANYMORE" option can save you a whole lot on efficiency.  

Yes, making a direct path from the net driver to the terminal driver is much
more efficient.  You do need the escape route however.  10 years ago (or was
that when it was done in ITS) there was talk of having the telnet server throw
such a switch, which meant "pass everything transparently between terminal and
net until you see a special character".  That would be IAC in the direction of
net->term and one of BREAKSET in the term->net direction.  Once the escape
character was encountered the server would have to interpret again, until it
was satisfied to put the path in transparent mode again.

     If there was a way to make sure that no more telnet options processing
     would need to be done, a similar thing could be done with telnet on
     other operating systems, saving 2 process-switches per character.

Since there is always option processing going on, you just invoke the server
for the characters it needs to handle.  IAC-IAC doubling would be expensive,
but how often do you transfer the character 0xFF?

Regards,
Mike