HP 3000 Manuals

Using NS3000/XL Network Services

Chapter 2  Virtual Terminal 

Virtual Terminal Overview 

In order to issue interactive commands to a remote operating system or to
a subsystem available on a remote computer, you must establish a session
on the remote node.  The Virtual Terminal service (VT) makes the fact
that the session is remote almost entirely transparent.  You enter
commands and receive system/subsystem responses at your local terminal
just as if your session were local.  When you edit text in a remote
editor subsystem, the text appears in the proper format on your local
terminal screen.  In reality, input and output to your local terminal
pass through a "virtual" (as opposed to actual, physical) terminal
configured on the remote system.  Your remote commands are transmitted
over network connections, sent to the virtual terminal, and subsequently
executed on the remote system.

Using the Virtual Terminal service, you can take advantage of a remote
system's processing capabilities.  For example, if a program needs to be
run on a remote node, you can use VT to access it, edit the program, and
then compile, load, and run it directly on the remote node.

The Reverse Virtual Terminal service enables an application process
within a node to communicate with a real terminal that is on its network
or internetwork.  The application's home node sets up a virtual terminal
for each real terminal that the application needs access to.  Information
sent from a terminal to the application process (or vice versa) passes
through the appropriate virtual terminal.  With Reverse VT, the
application process can accept input from all nodes, though individual
sessions are not established on each node.

Figure 2-1 is a schematic illustration of the Virtual Terminal (and
Reverse Virtual Terminal) service.  By using the NS3000/XL Virtual
Terminal service on a network, you can log on to any session-accepting
node in the network from your own local node.  All systems are
transparently accessible to each other.


          Figure 2-1.  Virtual Terminal Service 

In addition to your local session, you can also create multiple remote
sessions on your own local node or on remote nodes.  Optionally, you can
configure your own remote prompts, so that you can identify each remote
environment by its prompt.

In order to create a remote session, you can use either  REMOTE  : 
nodename followed by a logon, or, you can use  DSLINE  nodename followed
by a  REMOTE HELLO user.acct.  After using either the DSLINE command or
the  REMOTE HELLO command, you then use the  REMOTE command in order to
be able to use commands in the remote environment.  The following pages
will explain how to use these commands.

MPE/iX 5.0 Documentation