Article 127642 of comp.os.vms:
Path: nntpd.lkg.dec.com!depot.mro.dec.com!mrnews.mro.dec.com!mrlat.enet.dec.com!raspuzzi
From: raspuzzi@mrlat.enet.dec.com (Michael Raspuzzi)
Newsgroups: comp.os.vms
Subject: Re: Use a VAX/AXP with VMS as a LAT 'Terminalserver'
Date: 22 Aug 1995 13:37:05 GMT
Organization: Digital Equipment Corporation
Lines: 93
Distribution: world
Message-ID: <41cmi1$7d3@mrnews.mro.dec.com>
References: <DDGMK1.Btv@news.dlr.de>
Reply-To: raspuzzi@mrlat.enet.dec.com (Michael Raspuzzi)
NNTP-Posting-Host: mrlat.zko.dec.com
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In article <DDGMK1.Btv@news.dlr.de>, Michael.Zoellner@dlr.de  writes:
|>
|>
|>Hi,
|>
|>could anybody please tell me how to use a VMS system as a LAT 'terminalserver',
|>or why it is not possible?

The OpenVMS LAT software has all the hooks in it to actually do this.  The
LAT implementation on OpenVMS is fully functional (from the protocol's
perspective) but to make an OpenVMS system act like a terminal server, you
would have to write controlling software for hardwired ports and interface
from the hardwired ports to the LAT software.  I've thought about doing this
many times but have been just too busy to do so.

|>
|>I want to connect a modem via serial line to a VMS system and make a connection
|>via LAT from another computer to that modem. I know that this is possible using
|>a terminalserver. But I don't want to buy an extra one when I have a VAX with
|>unused serial ports.
|>

How about using an application service with dedicated ports?  You could then
write a .COM file to control the dedicated port and interface between the
user's LAT connection and the dialout modem.

For example, let's say you wanted OpenVMS to offer a LAT service called
"DIALOUT" and you wanted anyone who connected to that service to be able
to talk to a modem on TXA1.  First, you would write a command procedure
to control the LAT connection.  It could look something like this simple
example:

$loop:
$ open /read my_port LTA777:
$!
$! When user hits CRLF after connecting, this next line will
$! complete.
$!
$ read /prompt="" my_port my_data
$!
$! Make sure I/O goes to LTA device
$!
$ define sys$input lta777:
$ define sys$output lta777:
$ define sys$command lta777:
$ define sys$error lta777:
$!
$! Connect to dial out modem
$!
$ set host /dte txa1:
$!
$! User has exited DTEPAD - force LAT disconnect
$!
$ deassign sys$error
$ deassign sys$command
$ deassign sys$output
$ deassign sys$input
$ close my_port
$!
$! And loop up and wait for the next connection
$!
$ goto loop

Next, you setup the dedicated port and application service like this:

$ MCR LATCP CREATE PORT LTA777 /DEDICATED
$ MCR LATCP SET PORT LTA777 /SERVICE=DIALOUT
$ MCR LATCP CREATE SERVICE /APPLICATION DIALOUT /ID="Dialout modem"

Finally, fire off the command procedure with either "@" or RUN /DETACH.

The command procedure will set the reference count of LTA777 to a non-0
value when it opens a channel to it and that makes the device available
for connecting.  A user on a terminal server or another OpenVMS system
can then access the dial out modem like this:

Local> CONNECT DIALOUT
	or
$ SET HOST /LAT DIALOUT

And you can password protect the application LAT service like this:

$ MCR LATCP SET SERVICE DIALOUT /PASSWORD="pwd"

I make no warranties about the above command procedure.  It hasn't been
tested extensively and may require some tweaks to get it to work the way
you want.  The intent is to demonstrate how to use a dedicated port with
an application service to make a resource available to the LAN via the
LAT protocol.  I hope this helps.
-- 
Mike Raspuzzi (raspuzzi@mrlat.enet.dec.com)
Digital Equipment Corporation