3Com MSR 30, MSR 50 manual Lapb and X.25 Configuration Commands

458CHAPTER 26: LAPB AND X.25 CONFIGURATION COMMANDS

interface interface-typeinterface-number: Specifies an interface by its type and number.

dlci dlci-number: Specifies an DLCI. The dlci-numberargument is in the range 16 to 1007.

pvc pvc-number2: PVC number on the output interface, and its value ranges from 1 to 4095.

option: Attribute option of PVC.

Description for options:

■packet-sizeinput-packetoutput-packet: Specifies the maximum and output packet sizes in bytes, which range from 16 to 4096, and must be the integer power of 2.

■window-sizeinput-window-size output-window-size: Specifies the input and output window sizes of the VC. When the modulo is 8, it is in the range 1 to 7; when the modulo is 128, it is in the range 1 to 127.

Description Use the x25 switch pvc command to configure a PVC route.

Use the undo x25 switch pvc command to delete a PVC route.

By default, no PVC route is defined.

Based on the X.25 switching configuration, you can use the device as a simple X.25 switch. When PVC switching is configured, the link layer protocol on the input and output interfaces must be X.25. Moreover, the specified PVCs on the two interfaces are effective. After configuring the PVC switching route, the device will receive information from the PVC of the input interface and forward the information through the specified PVC of the output interface.

You can configure X.25 PVC switching to switch from an X.25 interface to an

Annex G DLCI (X.25 over FR) or vice versa, or even between Annex G DLCIs.

Two X.25 networks can be connected via an Annex G DLCI over an FR network. The Annex G DLCI can also act as a backup connection between the two X.25 networks.

You need to configure the switching route for the other interface when configuring switching; otherwise, the switching does not work.

For X.25 PVC switching, you need to specify the VC range first to make it work; otherwise, the PVC switching in the X.25 template cannot work unless you apply a new template to the FR DLCI or delete the current template.

Note that PVC switching cannot be configured on the X.25 sub-interface.

Example # Perform the packet switching from PVC1 on the Serial2/0 to PVC2 on the Serial2/1.