From mboxrd@z Thu Jan 1 00:00:00 1970 From: fair-tuhs@netbsd.org (Erik E. Fair) Date: Sun, 19 Mar 2017 18:25:03 -0700 Subject: [TUHS] 4.3BSD help: getty ignoring modem status In-Reply-To: <24849.1489970823@cesium.clock.org> References: Message-ID: <12242.1489973103@cesium.clock.org> One more thing: it's impossible to get an 8-bit clean connection through the TELNET protocol without speaking the TELNET protocol: even in binary mode, you have to escape IAC (0377, 0x7F) in transmission, and eat the IAC byte doubling in reception. See RFC-854. I wrote an implementation of TELNET specifically for the AppleLink/Internet E-mail gateway at Apple because we had to speak X.25 (sort of) to the GEIS network & mainframe, and I didn't want to buy system-specific, proprietary HDLC/LAPB serial gear that would lock me into a particular hardware platform, so I used a Cisco protocol translator instead - it could be configured to map a TELNET server connection to a given X.25/X.3 PAD call (akin to a terminal server in "milking machine" mode). Worked great, once I had that streaming TELNET implementation going to get binary data through the connection. That design left me free to run the gateway on any Unix system I felt like: it started on a Mac SE/30 (A/UX), moved to an SGI-4D/380 (Irix), and ended life on a Sun SPARCstation ... 10 or 20 (SunOS 4? Solaris? I forget). So long as the Unix in question had TCP/IP, Berkeley sockets, a network interface (preferably Ethernet), sendmail(8) and perl(1), the gateway could be run on it. Didn't even need to be proximate to the Cisco protocol translator - just somewhere on the same IP network. Most of the code was actually Perl 3 & 4 because E-mail gatewaying is mostly about string manipulation. happy solstice! Erik Fair