Re: Reverse Telnet Madness

mikehunt@algonet.se (Mike Johnson) writes: >Pete Stiglich (Pafc@news.oar.net) wrote: >: Hello, I am having a problem with running INformix programs on a terminal >: that is connected to our Sparc 10 Model 20 -- Solaris 2.3, through a >: Chase Research terminal server. It is connected via reverse telnet. >: I have enabled the port using pmadm, sacadm, etc. The user can login >: without any problems, do vi, mail, etc without ANY problems. However, >: when it comes to informix, it goofs up. For example, in a menu, the >: user normally only has to press the first letter, i.e. e for exit. But >: in this scenario, the user has to push e and hit return for it to take >: the action. It also echos everything back. I am using a wyse50 emulation >: and I've compared the stty settings between this terminal and my other >: terminals with the same emulation. >: Any HELP would be gratefully accepted. >This is the way a telnet connection works. You cannot run interactive >stuff like this over a telnet connection as the CR is the signal that >causes telnet to pass the buffer across the link. *Some* telnet >implementations can be made to work on a character basis IIRC but not >many. I've run vi and emacs over telnet connections for years, many times through terminal servers that run telnet sessions. I cannot offhand think of any that failed to support character mode. Typing the command "mode character" at the telnet> prompt will do this for the Solaris 2.3 telnet command (any most other UNIX telnets as well). Any decent terminal server should allow the user to select this mode at the server's prompt (the command to do so varies from server to server, of course), and moreover there should be a way for the system manager to set the server so that character mode is the default. The main advantage of line mode is that it reduces network load by combining a whole line into a single IP packet, thus avoiding the silliness of having to send several dozen bytes worth of network headers and trailers to transmit a single keystroke down the network. This is probably why the person responsible for the server chose line mode as the default. But as you discovered, the efficiency comes at the price of breaking any program that wants to to character-by-character I/O. -- David Barts N5JRN UW Civil Engineering, FX-10 davidb@ce.washington.edu Seattle, WA 98195 2201 GMT T: 55 F wind: W 6 gust 6 mph P: 1014 mbar