3com MSR 20-20 참조 매뉴얼

# Set the LAPB parameter N2 on Serial 2/0 to 20.

<Sysname> system-view

[Sysname] interface serial 2/0

[Sysname-Serial2/0] lapb retry 20 

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

undo lapb timer { t1 | t2 | t3 }

Interface view

t1 t1-value: Value of timer T1, in the range 2 to 64000 milliseconds. The default is 
3000 milliseconds.

t2 t2-value: Value of the timer T2, in the range 1 to 32000 milliseconds. The 
default is 1500 milliseconds.

t3 t3-value: Value of the timer T3, in the range 0 to 255 seconds. The default is 0 
seconds.

Use the lapb timer command to configure the LAPB timers T1, T2 and T3.

Use the undo lapb timer command to restore their default values.

T1 is the retransmission timer. When T1 expires, DTE (DCE) will start 
retransmission. The value of T1 shall be greater than the maximum time between 
the sending of a frame and the receiving of its response frame.

T2 is the reception timer. When it expires, the DTE/DCE must send an 
acknowledgement frame so that this frame can be received before the peer 
DTE/DCE T1 timer expires (T1Š2*T2).

T3 is an idle channel timer, when it expires, the DCE reports to the packet layer 
that the channel stays idle for a long time. T3 should be greater than the timer T1 
(T3>T1) on a DCE. When T3 is 0, it indicates that it does not function yet.

# Set the LAPB timer T1 on Serial2/0 to 2000 milliseconds.

<Sysname> system-view

[Sysname] interface serial 2/0

[Sysname-Serial2/0] lapb timer t1 2000 

lapb window-size k-value