3Com MSR 50 Series Configuration Manual page 315

LAPB Configuration Example 315
<RouterA> system-view
[RouterA] interface serial 2/0
# Assign an IP address for the interface.
[RouterA-Serial2/0] ip address 10.1.1.2 255.0.0.0
# Configure the link layer protocol of the interface as LAPB, and specify it to work
in DTE mode.
[RouterA -Serial2/0] link-protocol lapb dte
# Configure other LAPB parameters (If the link is sound enough and a higher rate
is desired, you can increase the traffic control parameters modulo to 128, k to
127, but the connected parties must always keep the configured parameters in
consistency.
[RouterA-Serial2/0] lapb modulo 128
[RouterA-Serial2/0] lapb window-size 127
[RouterA-Serial2/0] shutdown
[RouterA-Serial2/0] undo shutdown
2 Configure Router B.
# Enter interface view.
<RouterB> system-view
[RouterB] interface serial 2/0
# Assign an IP address for the interface.
[RouterB-Serial2/0] ip address 10.1.1.1 255.0.0.0
# Configure the link layer protocol of the interface as LAPB, and specify it to work
in DCE mode.
[RouterB-Serial2/0] link-protocol lapb dce
# Configure other LAPB parameters (If the link is sound enough and a higher rate
is desired, you can increase the traffic control parameters modulo to 128, k to
127, but the connected parties must always keep the configured parameters in
consistency.
[RouterB-Serial2/0] lapb modulo 128
[RouterB-Serial2/0] lapb window-size 127
[RouterB-Serial2/0] shutdown
[RouterB-Serial2/0] undo shutdown
Note that the IP addresses of the two connected interfaces must be in the same
network segment. If they are not on the same network segment, you need to
configure a static route in between and make sure the traffic control parameters
of both sides are the same.