3com 3031 Instruccion De Instalación

Configuring X.25

291

T2 is the receiving timer. When T2 timer reaches the designated time, DTE or (DCE)
must send a confirmation frame in order that the opposite DCE (or DTE) can
receive the confirmation frame before T1 times out (T2<T1).

LAPB T3 is the idle channel timer. When T3 timer reaches the designated time,
DCE reports the long-time idle channel state to the packet layer. T3 must be larger
than T1 in DCE (T3>T1). If T3 is 0, it indicates that the timer is not in function.

By default, T1 is 2000ms, T2 is 1000ms and T3 is 0ms.

Configuring X.25

X.25 configuration includes:

■

Configure X.25 interface

■

Configure X.25 interface options

■

Configure X.25 datagram transmission

■

Configure additional parameters of x.25 datagram transmission

■

Configure X.25 subinterface

■

Configure X.25 switching

■

Configure X.25 load sharing

Besides, appropriate modification on some LAPB parameters in certain cases can
also optimize the performance of X.25.

Configuring X.25

Interface

X.25 interface configuration tasks include:

■

Configure X.121 address

■

Set X.25 operating mode

■

Configure VC range

■

Configure packet numbering modulo

■

Configure the default flow control parameter (including window size and
packet length)

An interface should first be configured as an X.25 interface by performing the
following tasks before it can transmit data with the X.25 protocol.

In the following configurations, “Configuring X.25 working mode" is compulsory,
and other configurations are optional, which depends on the accessed X.25
network.

Table 349 Configuring the system timers T1 and T2 and T3 in LAPB

Operation

Command

Configure the system timers T1
and T2 and T3 in LAPB

lapb timer { t1 t1-value | t2 t2-value |
t3 t3-value }

Restore the default values of
LAPB timers T1, T2 and T3

undo lapb timer{ t1 | t2 | t3 }