3com 3031 Instruccion De Instalación

C

HAPTER

 26: X.25 

AND

 LAPB C

ONFIGURATIONS

XOT implementation principle (taking SVC as an example):

As shown in the above figure, when transmitting data, RouterA first sends a call 
request packet to establish VC. After receiving this call packet and judging it as 
XOT application, RouterB will establish a TCP connection with RouterC, then add 
XOT header to X.25 call packet and encapsulate it into TCP, finally transmit it to 
RouterC. After deleting TCP and XOT header, RouterC transfers the call request 
packet to RouterD via X.25 local switching. After receiving it, RouterD will give out 
call acknowledgement till the link is completely established and enters the data 
transmission status. The whole process for establishment and application of TCP 
connection is transparent for RouterA and RouterD that do not care whether data 
is forwarded via IP network or X.25 network.

XOT configuration includes:

■

Enabling X.25 switch

■

Configuring IP interface

■

Configuring local switching (SVC)

■

Configuring XOT route

■

Configuring Keepalive and xot-source attributes (optional)

■

Enable X.25 switching

Since XOT application is a extension of X.25 switching, X.25 switching must be 
enabled first.

1 Perform the following in the System View.

By default, X.25 switching is disabled.

2 Configure IP interface

To enable XOT application to implement the interconnection between X.25 
networks at both ends via IP network, IP network must operate well.

For the specific configuration, refer to Part V “Network Protocol”

3 Configure local switching (SVC)

After receiving the peer packet, SVC must send it via the local switching interface. 
Therefore, the local switching must be configured.

The following commands determine which switching interface will be selected by 
the SVC to send the packets reaching the local router.

Perform the following in the System View.

Table 383   Enabling X.25 switching

Enable X.25 switching

Table 384   Configuring local switching