Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!usc!samsung!xylogics!loverso.leom.ma.us!john From: john@loverso.leom.ma.us (John Robert LoVerso) Newsgroups: comp.protocols.tcp-ip Subject: Re: Making terminal servers just like internal serial ports Message-ID: <15Mar91.135921@loverso.leom.ma.us> Date: 15 Mar 91 19:09:14 GMT References: <1991Mar15.013603.18407@johnny5.uucp> Sender: loverso@Xylogics.COM Reply-To: John Robert LoVerso Organization: John & Sue's House, Leominster MA Lines: 25 Return-Path: John Robert LoVerso > Why doesn't anyone do this? Is there a protocol under developement? Some terminal server vendors do let you do this. There are several ways. The easiest involves something on the order of a user-level "reverse" telnet daemon that runs on your host, connects to a pty pair, and makes a telnet connection to the terminal server. This gives you a device that you can poke random programs at. Xylogics provides source to such a program with the software distribution that comes with the Annex. cisco provides a similiar program via anonymous ftp access. One or two other such programs have been posted to comp.sources in the past. The pty approach has several hazzards, as it stretches the abilities of the pty mechanism in various ways. However, it is a good 90% solution. Of course, it can reek havoc with the performance of your machine - as can anything based upon the traditional BSD telnetd/pty interaction. Using the "in-kernel" telnetd support code can remove this performance problem. At least one company (Artecon) resells [Annex] terminal serves with a SunOS device driver that does the telnet connection in the kernel and links directly to the tty stack. This supposedly removes several of the problems with the pty approach, but I've never used it, so I can't comment further. John