I don't think I really need a lot of control of the tty settings
sent to the other end.

The devices on the other end are not actually modems, that
was just my example. The devices will have a fixed set of
serial settings set on the terminal servers serial port.
All I really need is the stream of data sent down the ip pipe
from the tty to the terminal server.

We have done this numerous times using ip sockets directly
on the application end, but this custom application cannot be
modified and only talks to ttys. I thought this would be a good
solution.

Is this conceivably possible ?

Thanks for everyones help.

Scott..


-----Original Message-----
From: Greg A. Woods [mailto:woods@weird.com]
Sent: Sunday, February 24, 2002 3:25 PM
To: Scott R. Burns
Cc: netbsd-users@netbsd.org
Subject: Re: tty driver for reverse telnet (a better explanation)


[ On Sunday, February 24, 2002 at 09:56:34 (-0500), Scott R. Burns wrote: ]
> Subject: tty driver for reverse telnet (a better explanation)
>
> I want to create a /dev/ttyabc entry which when open() is used on it
> causes it to telnet to terminalserver.company.com port 3001 for example.
> Much like you would say telnet terminalserver.company.com 3001 to connect
> to a modem hung off a terminal server port and offered on the terminal
> server via reverse telnet. Does that make any sense ?

Lots-o-sense!  ;-)

Livingston Portmasters used to come with such a driver.  They didn't use
plain telnet as the protocol for the connection though because telnet
alone doesn't have enough support to pass through some of the tty
settings.  Perhaps xylogics had such a driver too, but I don't remember.

Note that without similar special support in the terminal server you
won't be able to pass on many stty (termios) settings.

I did most of the design for such a protocol and driver about 8 years
ago, just before modems started to fall out of favour, and when a real
terminal server was priced a bit too high for the non-profit I was
working for at the time.  We never implemented it though because we were
able to farm out the modem pool to an internet provider.

> This allows programs written with only tty support to connect over the
> lan to devices hung off of terminal servers.

What programs are you thinking of?  I know of no such programs which
won't also need full, or nearly full, termios support.  Some of them
might get by with faked controls, and with a full telnet daemon on the
other end some termios changes can be translated into telnet options and
negotiated, but that's about as far as you'll get.

--
								Greg A. Woods

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