Configuring and Managing Host-Based X.25 Links - Edition 6 (36939-90057)

Introduction
Connections via PAD Support
Chapter 1
21
Connections via PAD Support
Remote terminal users connecting via the DTCs PAD support use X.25 addresses to
establish the connection to the DTC. When you configure PAD support on the DTC, you
configure a PAD switching information table, which maps X.25 addresses to local
systems. A remote terminal user who enters one of these X.25 addresses is automatically
connected to the corresponding system. Users connection via PAD support can only open
one session at a time
There are two methods of giving PAD-connected terminal users access to multiple
systems.
• For each system to which they are to connect, you map an X.25 address to the system
nodename in the PAD Switching Table. Users use the appropriate X.25 address to
connect to the system. This method ensures that PAD users are restricted to the
systems that you explicitly allow them to access. When the user logs off the system,
they are returned to the PAD prompt, not to the DTC user interface. Up to 32
systems can be configured in this way.
• You can also configure an X.25 address that gives access to the DTC user interface.
PAD users connected to the DTC user interface can connect to any system on the
LAN in the same ways as asynchronously-connected terminal users, using system
names or IP addresses. Note, however, that PAD users cannot use the
escape-from-the-data-transfer facility of the DTC to suspend a system session and
return to the DTC user interface. They must log off the system to return to the user
interface.
PAD Access
The PAD access table is used:
• to map calling PAD address to nailed ldevs on MPRE/iX systems
• to map PAD device numbers to X.25 addresses for the HP DTC Device Files Access
utility on HP-UX systems
• for programmatic access to remote PAD devices
• for device profile selection
The PAD Access table lists device names or numbers of remote PAD devices with X.25
address, closed user group (CUG) numbers and devices profiles. This list enables an
incoming call to be tied to a nailed ldev on an MPE/iX system or PAD devices access via
the HP DTC Device File Access (DDFA) software on an HP-UX system. The PAD device
name is used to associate with a PAD address that is downloaded to the DTC with
particular nailed ldev on the MPE host. If you want to have a nailed PAD devices on a
non-managed DTC, then configure the PAD device with the same device name on the
system where the DTC is a non-managed DTC.
If you are configuring PAD connections, you can also configure PAD Incoming Security.
The PAD incoming security feature maps X.25 addresses of remote PAD devices to access
lists. The access lists list the LAN-based systems that the remote device is permitted to
access. An access list may optionally have a password. The names of all the nodes to be
accessed through the managed DTCs of a system must first be entered into the node
names list. The access lists are subsets of the nodenames list, and only nodes that