433tcp peer ip: 10.1.1.1, peer port: 1998tcp local ip: 10.1.1.2, local port: 1024socket keepalive period: 5, keepalive tries: 3come interface name: Serial1/0-10.1.1.1-1024go interface name: Serial1/0lapb max-frameSyntax lapb max-frame n1-valueundo lapb max-frameView Interface viewParameter n1-value: N1 value of the LAPB parameter in bits, in the range 1096 to 12104. It isthe maximum value of a frame expected from the DTE or DCE, 8 times the valueof MTU plus the protocol header.Description Use the lapb max-frame command to configure the LAPB N1 parameter.Use the undo lapb max-frame command to restore the default.The default value of N1 is calculated according to the MTU, upper layer protocoland modulo, as shows below:The default value of N1 varies with MTU and modulo.For example, upon system initialization, the upper layer protocol is IP, modulo 8and MTU 1500, so the default value of N1 is (1500+4)*8 = 12032. If the modulois set to 128, then the default value of N1 is (1500+5)*8 = 12040. You can use theundo lapb max-frame command to restore the new default. For the samereason, N1 changes with the change of MTU.Example # Set the LAPB N1 parameter to 1160 on Serial 2/0. system-view[Sysname] interface serial 2/0[Sysname-Serial2/0] lapb max-frame 1160Table 64 Difference between N1 and MTU (in bytes) versus upper layer protocol andmoduloUpper layer protocol ModuloDifference between N1 andMTU (bytes)IP/IPX 8 4IP/IPX 128 5Multiprotocol 8 6Multiprotocol 128 7X.25 8 7X.25 128 8
