User manual

7 LAPB and X.25 configuration
Nortel Secure Router 8000 Series
Configuration -WAN Access
7-30 Nortel Networks Inc. Issue 5.3 (
30 March 2009)
A packet network consists of many nodes interconnected in a certain topological structure.
From the source to its destination, a packet passes through many nodes, each of which must
have packet switching capability.
X.25 packet switching receives packets from one X.25 port, and sends them out of the X.25
port selected according to related destination address information contained in the packets.
X.25 switching enables the SR8000 to perform packet switching function in the packet layer.
If a Nortel router is used, X.25 switching enables it to serve as a small packet switching
exchange.
The SR8000 provides the following X.25 switching functions:
z
SVC switching function
z
Parameter negotiation on window size and packet size
z
PVC switching
Figure 7-9 X.25 switching networking diagram
PC
x.25 host
PC
x.25 host
The disabling/enabling of X.25 switching affects only the creation of a call, and has no effect
on the created links.
You cannot configure the switching route until X.25 switching is enabled.
If you disable the switching after the undo x25 switching command is run when certain
switching routes are configured, then all the static SVC routes are invisible except for PVC,
which is visible if you run the display command. In this case, if you use the save command
and reboot the router, all SVC routes are lost and PVC routes cannot be resumed. Later, if you
run the x25 switching command, PVC routes can be resumed; however, PVC must be
manually deleted.
After the configuration, use the display x25 switch-table svc command to display the
switching route table.
7.4.5 Checking the configuration
Run the following commands to check the previous configuration.
Action Command
Check information about
the interface.
display interface [ serial number ] [ | { begin | exclude |
include } regular-expression ]
Check the X.25 alias
table.
display x25 alias-policy [ interface serial slot-number ]
Check the X.25 address
mapping table.
display x25 map