X25AM Configuration and Management Manual

Overview of the X25AM Subsystem

X25AM Configuration and Management Manual—523424-004

2-4

Packet Assembler/Disassembler (PAD)

X25AM comes with its own software PAD application for your convenience. The X.3

Packet Assembler/Disassembler (X3PAD) program enables a user at an interactive

(conversation-mode) terminal connected to an Integrity NonStop NS-series or

NonStop S-series server to access other systems through a PSDN. X3PAD does not

support block-mode terminals. Some input sources that can be used to communicate

through X3PAD are:

•

65xx terminals

•

HP emulator terminals

•

TELSERV-connected Network Virtual terminals

X3PAD passes data between the user terminal and the network. Functions performed

by X3PAD can be controlled by commands issued from the terminal or by PAD

messages issued from the network. X3PAD can also transfer data from NonStop

server files to the network or from the network to NonStop server files.

The X3PAD program is based on the ITU-T Recommendation X.3, which describes the

functions of a PAD and the parameters associated with the asynchronous terminals

accessing the PAD.

X3PAD also supports the procedures of Recommendation X.29, which describes the

communications between a PAD and a packet-mode DTE using a PSDN. For detailed

information about the default PAD parameter values for X3PAD, and the commands

you can use to change them, see the X25AM Programming Manual.

Subscription Parameters

The X.25 ITU-T Recommendation provides various configuration options that affect

how your connection to the network operates. The value or range of values for these

options depends on the network. These options are called subscription parameters or

user facilities. A few of the subscription parameters affect all calls.

Some of these subscription parameters are specified by X25AM I/O process modifiers

(see Table 2-1 on page 2-5) using SCF commands to the WAN subsystem; such

modifiers are described in Section 3, Configuring an X25AM Subsystem.

Most subscription parameters are requested on a per-call basis; such parameters can

be specified using:

•

SCF commands with line attributes to the X25AM subsystem

For information about these parameters, see Section 4, SCF Commands for the

X25AM Subsystem and Section 5, Attribute Descriptions.

•

File-system procedures

For information on subscription parameters that can be requested for each call,

see the X25AM Programming Manual