AI2524 Router Card User’s Manual

Configure Interface

Note:

If you connect a router to an X.25 network, use the

 

parameters set by your network administrator for th

 

connection; these parameters will typically be thos

 

described in the Configure Interface and Modify LAPB

 

Protocol Parameters sections. Also, note that the X.25

 

Level 2 parameters described in the Modify LAPB

 

Protocol Parameters section affect X.25 Level 3

 

operations.

To configure an X.25 interface, perform these tasks:

zSet the X.25 Mode

zSet the Virtual Circuit Ranges

zSet the Packet Numbering Modulo

zSet the X.121 Address

zSet the Default Flow Control Values

These tasks describe the parameters that are essential for correct X.25 behavior. The first task is required. The others might be required or op- tional, depending on what the router is expected to do and on the X.25 network.

Set the X.25 Mode

A router using X.25 Level 3 encapsulation can:

zAct as a DTE or DCE protocol device (according to the needs of your X.25 service supplier)

zUse the Internet Engineering Task Force (IETF) standard encap- sulation, as specified by RFC 1356.

Because the default serial encapsulation is High-level Data Link Con- trol (HDLC), you must explicitly configure an X.25 encapsulation method.

In interface configuration mode, configure the mode of operation and one of these encapsulation types for a specified interface:

encapsulation x25 [dte dce] [ietf]]

Typically, a Public Data Network (PDN) will require attachment as

DTE. This requirement is distinct from the hardware interface DTE or

DCE identity.

The default mode of operation is DTE, and the default encapsulation method is Cisco's pre-IETF method.

Page 12-2

August 1997

 

2524UM

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AIS AI2524 user manual Configure Interface, Set the X.25 Mode