TCP/IP TELNET Management Programming Manual

1 Introduction
53474 Tandem Computers Incorporated 1–1
This section introduces the Tandem TCP/IP TELNET subsystem, the objects controlled
by the TELNET subsystem, and the management concepts applicable to the TELNET
subsystem.
Some of the concepts discussed here include the monitoring and control functions
available and the relationship of the TELNET subsystem to other Tandem subsystems.
Brief Overview of
TELNET
The TELNET subsystem is Tandem’s implementation of the TELNET server portion of
the TELNET protocol. The TELNET protocol is a general, bidirectional, eight-bit byte-
oriented protocol in the Transmission Control Protocol/Internet Protocol (TCP/IP)
protocol suite that provides a standard method of interfacing terminal devices and
terminal-oriented processes to each other. A TELNET connection is a TCP connection
that contains TELNET control information.
The Tandem TELNET server (otherwise known as the TELNET subsystem) provides
TELNET services to both Tandem TELNET clients (including the TN6530 client) and
other TELNET clients in the internet. For further details on the specific services
supported by the Tandem TELNET server (including the requests, line control
functions, options, and commands), refer to the Tandem TCP/IP Application User’s
Manual.
The TELNET subsystem runs as a single process on the GUARDIAN 90 operating
system and uses the sockets library routines of the Tandem TCP/IP software for TCP
access. (The TELNET process does not currently run as a NonStop process pair.) The
Tandem TCP/IP software runs over the Tandem LAN Access Method (TLAM) I/O
process for access to Ethernet-based local area networks. For further details on the
relationship between the Tandem TCP/IP software, the TELNET protocol, the
TELNET subsystem, the Tandem TELNET client software, and other TELNET client
software, refer to the Tandem TCP/IP Manual.
Objects Controlled by
the Subsystem
The TELNET subsystem defines two types of objects: a process and windows. The
process object is the TELNET interface, which is accessed by an application program or
the Subsystem Control Facility (SCF) by means of the Subsystem Control Point (SCP).
The process object must be a GUARDIAN 90 named process.
A Tandem system can support only one TELNET (server) process per TCP/IP process.
System configuration is not required for the TELNET process; you create the process
with the RUN command.
The following two examples show commands for creating a TELNET process:
1> RUN $SYSTEM.SYS03.TELSERV/NAME $ZTNT,NOWAIT,CPU 0, PRI 170/
or
2> TELSERV/NAME $ZTNT,NOWAIT,CPU 0, PRI 170/
For a detailed description of the RUN command for the TELNET subsystem, see the
Tandem TCP/IP Management and Operations Manual.