3Com Router 3031, Command Reference Manual

Page: 375 / 838

LAPB and X.25 Configuration Commands 375
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threshold in out: When the address mapping is used to originate a call, it
negotiates throughput with the peer end. The values of in/out are defined to
be 75, 150, 300, 600, 1200, 2400, 4800, 9600, 19200, and 48000.
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vc-per-map count: Maximum number of VCs associated with the address
mapping.
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window-size input-window-size output-window-size: When the address
mapping is used to originate a call, it negotiates the window size with the peer
end. The values of input-window-size and output-window-size range between
1 and the number that is 1 less than the modulus of the X.25 interface where
the address mapping exists (including 1 and modulus minus 1).
For the related commands, see display x25 map, x25 reverse-charge-accept, x25
call-facility, x25 timer idle, and x25 vc-per-map.
Example
Set two address mappings on the X.25 interfaces Serial0/0/0 and Serial1/0/0,
respectively, and the four address mappings have different attributes.
[3Com] interface serial 0/0/0
[3Com-Serial0/0/0] x25 map ip 202.38.160.11 x121-address 20112451
reverse-charge-request reverse-charge-accept
[3Com-Serial0/0/0] x25 map ip 202.38.160.138 x121-address 20112450
packet-size 512 512 idle-timer 10
[3Com] interface serial1/0/0
[3Com-Serial1/0/0] x25 map ip 20.30.4.1 x121-address 25112451
window-size 4 4 broadcast
[3Com-Serial0/0/0] x25 map ip 20.30.4.8 x121-address 25112450
no-callin
x25 modulo
Syntax
x25 modulo modulus
undo x25 modulo
View
Interface view
Parameter
modulus: Modulus, whose value is 8 or 128.
Description
Using the x25 modulo command, you can set the window modulus of an X.25
interface. Using the undo x25 modulo command, you can restore its default
window modulus.
By default, the window modulus of X.25 interface is modulus 8 mode.
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