| X.25 uses a sliding
window for flow control. Larger windows allow more packets to be in
transit. A larger VC window size allows more packets in the network
between the two VC endpoints. Windows and modulo values should match
at both ends of the X.25 link. A larger LAPB window size allows more
frames to be in transit between the immediate DTE/DCE connection.
Use the x25 win
and x25
wout commands to set the default window size. The window size
specifies the number of packets that can be received or sent without
receiving or sending an acknowledgment. Both ends of an X.25 link
must use the same default window size.
Therefore, to specify default
unacknowledged packet limits, use the following commands:
Router(config-if)#x25 win
packets
Router(config-if)#x25
wout packets
Table
describes the x25 win
and x25 wout
commands.
The x25 modulo command
specifies the packet-numbering modulus. It affects the maximum
number of window sizes. Modulo 8 is widely used and allows VC sizes
up to 7 packets. Modulo 128 is rare, but it allows VC window
sizes up to 127 packets.
The command to define packet-level
window counter limits follows:
Router(config-if)#x25
modulo modulus
Table
describes the x25 modulo command. Both ends of an X.25
link must use the same modulo.
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