Pad Remote Access Service; Introduction To X.25 Pad - 3Com MSR 50 Series Configuration Manual

X.25 PAD Remote
Access Service

Introduction to X.25 PAD

To do...
Enable CUG function and
configure suppression policy
Configure a local CUG to
network CUG mapping and
define suppression rule
n
The x25 cug-service and x25 local-cug commands are supported only on the
X.25 DCE interface, that is, you need to specify the interface as DCE when
encapsulating X.25 protocol on the serial interface.
Packet assembly/disassembly (PAD) is an X.25 specific concept.
Traditionally, only X.25 terminals could connect to an X.25 network. These
terminals must be packet terminals that support X.25 procedures in terms of
hardware and software. However, many terminals in common use are non-X.25
terminals. They either have no intelligence available with packet terminals or have
intelligence but do not support X.25 procedures. Examples of such terminals are
keyboards, monitors, and printers. To allow these devices to communicate on X.25
networks, X.25 PAD was developed.
X.25 PAD provides a mechanism to connect non-X.25 terminals to an X.25
network. As shown in the figure below, a PAD facility is placed between non-X.25
terminals and an X.25 network, allowing them to communicate with other
terminals across the X.25 network.
Figure 65 Interfacing function of PAD
X.25 network
X.25 PAD functions to provide:
X.25 procedures support for connectivity and communication with X.25
■
networks
Non-X.25 procedures support for connectivity with non-X.25 terminals.
■
Capabilities allowing non-X.25 terminals to set up calls, transmit data, and
■
clear calls.
Capabilities allowing non-X.25 terminals to observe and modify interface
■
parameters to accommodate to different terminals.
Use the command...
x25 cug-service
[ incoming-access |
outgoing-access | suppress { all |
preferential } ] *
x25 local-cug local-cug-number
network-cug
network-cug-number
[ no-incoming | no-outgoing |
preferential ]*
X.25 procedure
X.25 PAD Remote Access Service
Remarks
Required
Disabled by default
Required
Not configured by
default
Non-X.25
terminal
Non-X.25
procedure
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