Lapb And X.25 Configuration Commands; Lapb Configuration Commands; Lapb Max-Frame - HP MSR series Command Reference Manual

LAPB and X.25 configuration commands

The MSR 900 and MSR 93X routers do not support LAPB or X.25.

LAPB configuration commands

lapb max-frame

Use lapb max-frame to configure the LAPB N1 parameter.
Use undo lapb max-frame to restore the default.
Syntax
lapb max-frame n1-value
undo lapb max-frame
Default
The value of N1 is calculated according to the MTU, upper layer protocol, and modulo.
Views
Interface view
Default command level
2: System level
Parameters
n1-value: N1 value of the LAPB parameter in bits, in the range 1096 to 12104. It is the maximum number
of I frames expected from the DTE or DCE, 8 times the value of MTU plus the protocol header.
Usage guidelines
Table 67 Difference between N1 and MTU versus upper layer protocol and modulo
Upper layer protocol
IP/IPX
IP/IPX
Multiprotocol
Multiprotocol
X.25
X.25
The default value of N1 varies with MTU and modulo.
For example, on system initialization, the upper layer protocol is IP, modulo 8 and MTU 1500, so the
default value of N1 is (1500+4)*8 = 12032. If the modulo is set to 128, then the default value of N1 is
Modulo
8
128
8
128
8
128
328
Difference between N1 and
MTU (in bytes)
4
5
6
7
7
8