3Com Router 3031, Command Reference Manual

Page: 364 / 838

364 C
HAPTER
4: L
INK
L
AYER
P
ROTOCOL
View
Interface view
Parameter
k-value: Maximum number of I frame of unacknowledged sequence number that
DTE or DCE may send, if the modulus is 8, the value of the window parameter K
ranges 1 to 7. If the modulus is 128, the value of the window parameter K ranges
1 to 127. By default, the window parameter K is 7.
Description
Using the lapb window-size command, you can configure the LAPB window
parameter K. Using the undo lapb window-size command, you can restore the
default value of the LAPB window parameter K.
The value of the window parameter K is determined by the value of modulus.
For the related command, see lapb modulo.
Example
Set the LAPB window parameter K on the interface Serial 0/0/0 to be 5.
[3Com-Serial0/0/0] lapb window-size 5
link-protocol lapb Syntax
link-protocol lapb [ dte | dce ] [ ip | multi-protocol ]
View
Interface view
Parameter
■
dte: Indicates that the interface works in DTE mode of LAPB.
■
dce: Indicates that the interface works in DCE mode of LAPB.
■
ip: Indicates that the network layer protocol borne by LAPB is IP.
Description
Using the link-protocol lapb command, you can specify the link layer protocol of
the interface as LAPB.
By default, DTE is the default LAPB operating mode. IP is the default network layer
protocol.
Though LAPB is a layer-2 protocol of X.25, it can act as an independent link-layer
protocol for simple data transmission. Generally, LAPB can be used when two
routers are directly connected with a dedicated line. At that time one end works in
the DTE mode, and the other in the DCE mode.
For the related command, see display interface.