3Com 10014299 Network Router User Manual


 
Configure X.25 207
Configure X.25
Datagram Transmission
The configuration of X.25 datagram transmission includes:
Create the mapping from the protocol address to X.121 address
Create the permanent virtual circuit
In the most frequently used X.25 service, data is transmitted remotely between
two hosts using the X.25 protocol via X.25 public packet network. As shown in
the figure below, LAN A and LAN B are far apart, and X.25 packet switching
network can be used to realize information exchange between them.
Figure 63 LAN interconnection via X.25
The datagram uses IP address to communicate data and information between LAN
A and LAN B, whereas X.121 address is used inside X.25. Therefore, we setup
correct mapping between the IP address and X.121 address.
1 Create the mapping from the protocol address to X.121 address
An X.25 interface has its own X.121 address and inter-network protocol (such as
IP protocol) address. When X.25 initiates a call through this interface, the source
address (calling DTE address) it carries in the call request packet is the X.121
address of this interface.
For a datagram with a definite destination IP address, its corresponding X.121
destination address is located by the configured address mapping. The called
destination, just like a calling source, also has its own protocol address and X.121
address. Establish the mapping between the destination protocol address and the
X.121 address at the calling source, you can find the destination X.121 address
according to the destination protocol address, and successfully initiate a call.
In the interface view, perform the following commands to create/delete an address
mapping.
Table 246 Create/Delete the mapping from the protocol address to X.121 address
The protocol-address and x.121-address in the command line refer to the protocol
address and X.121 address of the destination, not those of the source.
An address mapping should be created for every destination.
While creating an address mapping, specify its attributes with the option items.
The meanings and specific content of these options will be described in
subsequent sections.
2 Create the permanent virtual circuit (PVC)
A permanent virtual circuit can be created for large-traffic and stable data
transmission on leased line. Permanent virtual circuits (PVCs) do not need any call
X.25
LAN A
Router A
LAN B
Router B
Operation Command
Create the mapping from the destination
protocol address to X.121 address
x25 map { ip | ipx }
protocol-address x121-address
x.121-address [ option ]
Delete the mapping from the destination
protocol address to X.121 address
undo x25 map protocol
protocol-address