User's Manual

Table Of Contents
Fortress ES-Series CLI Guide: Networking and Radio Configuration
64
acknowledgement is sent for each frame received, and if no
acknowledgement is sent the frame is retransmitted.
FragThreshold is set in bytes:
256
2345
, or the function can
be turned
off
(the default).
Fragmentation becomes an advantage in networks that are:
experiencing collision rates higher than five percent
subject to heavy interference or multipath distortion
serving highly mobile network devices
A relatively small fragmentation threshold results in smaller,
more numerous frames. Smaller frames reduce collisions and
make for more reliable transmissions, but they also use more
bandwidth. A larger fragmentation threshold results in fewer
frames being transmitted and acknowledged and so can
provide for faster throughput, but larger frames can also
decrease the reliability with which transmissions are received.
The RTS threshold (
RtsThreshold) allows you to configure the
maximum size of the frames the BSS sends without using the
RTS/CTS protocol. Frame sizes over the specified threshold
cause the BSS to first send a Request to Send message and
then receive a Clear to Send message from the destination
device before transmitting the frame.
The RTS protocol threshold is set in bytes:
1
2345
, or the
function can be turned
off
(the default).
The smaller the RTS threshold, the more RTS/CTS traffic is
generated at the expense of data throughput. On large busy
networks, however, RTS/CTS speeds recovery from radio
interference and transmission collisions, and a relatively small
RTS Threshold may be necessary to achieve significant
improvements.
3.4.9.8 BSS DTIM Beacon Countdown
NOTE: The beacon
interval is config-
ured with
set radio
-beaconint
, as des-
cribed in Section 3.4.3.
APs buffer broadcast and multicast messages for devices on
the network and then send a Delivery Traffic Indication
Message to “wake-up” any inactive devices and inform all
network clients that the buffered messages will be sent after a
specified number of beacons have been transmitted.
The value specified with
-dtim determines the number of
beacons in the countdown between transmitting the initial
DTIM and sending the buffered messages.
Set the DTIM beacon countdown (
-dtim) in whole numbers:
1–255
, inclusive (the default is
1
).
A longer DTIM beacon countdown conserves power by
permitting longer periods of inactivity for power-saving devices,
but it also delays the delivery of broadcast and multicast
messages. Too long a delay can cause multicast packets to go
undelivered.