TCP/IP Management Programming Manual

HP NonStop TCP/IP Management Programming Manual—529636-001
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1 Introduction
This section introduces the TCP/IP subsystem and describes management concepts
applicable to the TCP/IP subsystem. Some of the concepts discussed are the types of
objects controlled by the TCP/IP subsystem and the monitoring and control functions
available.
Brief Overview of TCP/IP
The TCP/IP protocols are a family of data communications protocols that allow
communication between heterogeneous systems in a multinetwork environment known
as the Internet. In the NonStop environment, this allows for communication between
UNIX and NonStop systems.
The NonStop TCP/IP subsystem actually consists of a variety of products in the
TCP/IP protocol family and provides services at the Network through Application
Layers of the OSI Reference Model. The NonStop TCP/IP subsystem is the base
subsystem for all the other components of the NonStop TCP/IP software. It provides a
file-system interface to the TCP, UDP (User Datagram Protocol), and IP.
The TCP/IP subsystem runs as a single or dual process on the NonStop operating
system and contains three I/O interfaces: an Ethernet interface, a Sub-network Access
Protocol (SNAP) interface, and an X.25 interface. The Ethernet interface uses the
ServerNet LAN Systems Access (SLSA) subsystem to provide access to Ethernet local
area networks (LANs) using the Digital-Intel-Xerox (DIX) protocol. The SNAP interface
uses the SLSA 802.2 LLC1 filter to provide access to Ethernet LANs using the IEEE
802.3 CSMA/CD protocol and token ring LANs using IEEE 802.5. The X.25 interface
uses the HP X.25 Access Method (X25AM) to provide access to the Defense Data
Network (DDN), X.25-based public data networks (PDNs), and other X.25-based
networks. This X.25 interface is used to create virtual circuits to remote hosts, so that
IP datagrams can be sent over these virtual circuits.
The TCP/IP subsystem does not currently run as a Nonstop process pair.
For further details about the components of the NonStop TCP/IP software and the
services they provide, see the TCP/IP Configuration and Management Manual.
Objects Controlled by the Subsystem
You can manage the TCP/IP subsystem programmatically or interactively by sending
commands that act on one or more DSM-related objects. The TCP/IP subsystem
defines three types of objects: processes, subnets, and routes.
PROC Object
The process (PROC) object is the TCP/IP interface, which is accessed by an
application program or the Subsystem Control Facility (SCF) by means of the