3Com 10014299 Typi cal X. 25 Configuration

224 CHAPTER 16: CONFIGURING LAPB AND X.25
[Router-Serial0]lapb module 128
[Router-Serial0]lapb window-size 127
2Configure Router B:
aSelect interface
[Router]configure
[Router]interface serial 1
bSpecify IP address for this interface
[Router-Serial1]ip address 202.38.160.2 255.255.255.0
cConfigure the link layer protocol of the interface to LAPB and specify its
working mode as DCE
[Router-Serial1]link-protocol lapb dce
dConfigure other LAPB parameters (if the link quality is good, and a higher rate
is required, the flow control parameter modulo can be increased to 128, k to
127, but they must be the same for both ends in the direct connection)
[Router-Serial1]lapb modulo 128
[Router-Serial1]lapb window-size 127
Typi cal X. 25
Configuration
Example
Back to Back Direct
Connection of Two
Routers via Serial
Interface
I. Networking Requirement
As shown in the diagram below, two routers are to be directly connected back to
back; the X.25 protocol is used between the serial ports for IP data packet
transmission.
II. Networking Diagram
Figure 68 Direct connection of two routers via serial ports
III. Configuration Procedure
1Configure Router A:
aSelect interface
[Router]interface serial 0
bSpecify IP address for this interface
[Router-Serial0]ip address 202.38.160.1 255.255.255.0
cConfigure the link layer protocol of the interface to X.25 and specify its
working mode as DTE
[Router-Serial0]link-protocol x25 dte
dSpecify X.121 address of this interface
[Router-Serial0]x25 x121-address 20112451
V.24/V.35 cable
Router A Serial 1
Serial 0 Router B