R2511-HP MSR Router Series Layer 2 - WAN Command Reference(V5)

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[Sysname-Serial2/1] x25 map ip 202.38.160.138 x121-address 20112450 packet-size 512 512
idle-timer 10
[Sysname-Serial1/0] quit
[Sysname] interface serial2/0
[Sysname-Serial2/0] x25 map ip 20.30.4.1 x121-address 25112451 window-size 4 4 broadcast
[Sysname-Serial2/0] x25 map ip 20.30.4.8 x121-address 25112450 no-callin
Related commands
• display x25 map
• x25 reverse-charge-accept
• x25 call-facility
• x25 timer idle
• x25 vc-per-map
x25 modulo
Use x25 modulo to set the modulo mode of the X.25 interface.
Use undo x25 modulo to restore the default.
Syntax
x25 modulo { 8 | 128 }
undo x25 modulo
Default
The modulo mode of the X.25 interface is 8 mode.
Views
Interface view
Default command level
2: System level
Parameters
8: Uses modulo 8 mode.
128 : Uses modulo 128 mode.
Usage guidelines
The slip window is the basis for X.25 traffic control, and the key about the slip window is that the sent
packets are numbered cyclically in order and are to be acknowledged by the peer end. The order in
numbering refers to the ascending order, like "…2, 3, 4, 5, 6…." "Cyclically" means that the numbering
starts again from the beginning when a certain number (called "modulo") is reached. For example,
when the modulo is 8, the numbering goes "…4, 5, 6, 7, 0, 1…."
X.25 defines the following numbering modulos: 8 (also called "basic numbering") and 128 (also called
"extended numbering").
The packet numbering mode on the pair of DTE and DCE must be the same.
Use the shutdown and undo shutdown commands on the interface to apply the new configuration.
The packet numbering mode of X.25 Layer 3 is different from the frame numbering mode of LAPB (Layer
2 in X.25). When modulo 128 is applied to the DTE/DCE interface with high throughput, it improves only