3Com AirConnect 9550, User Manual

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54 Service
Ack-Policy - when the Ack-Policy is checked. The device will not
send ACK frames. The default value is disabled.
Setting Description
Min Contention
Window For each access category, enter the minimum
contention window value. Channel access is
prioritized by assigning smaller contention
window values to a higher priority traffic class. If a
channel is busy or a transmission collides, a node
chooses a random number between 0 and the
current contention window minimum.
Max Contention
Window For each access category, enter the maximum
contention window value. The minimum
contention window value is doubled each time a
collision occurs until the maximum is reached. A
small contention window value decreases the
access delay but increases the probability of a
collision.
Fixed Slot Time For each access category, enter the fixed slot time.
Channel access can be strictly prioritized by
assigning smaller contention window values to a
higher priority traffic class. Traffic in the access
category must wait for this fixed number of slots
after each packet is received before resuming its
random back-off.
Transmit
Opportunity Limit Enter the number of microseconds that qualified
transmitters can transmit through the normal
back-off procedure with a set of pending packets.
Larger values allow a client to control the channel
for longer periods of time, allowing it to achieve
higher throughput in this access category at the
expense of longer access times for all access
categories.