Cisco WAP121 Administration Manual page 63

Wireless Settings
Radio
Cisco Small Business WAP121 and WAP321 Wireless-N Access Point with PoE
The measurement is in beacons. For example, if you set this field to 1, clients
will check for buffered data on the WAP device at every beacon. If you set
this field to 10, clients will check on every 10
• Fragmentation Threshold—The frame size threshold in bytes. The valid
integer must be even and in the range of 256 to 2346.
The fragmentation threshold is a way of limiting the size of packets (frames)
transmitted over the network. If a packet exceeds the fragmentation
threshold you set, the fragmentation function is activated and the packet is
sent as multiple 802. 1 1 frames.
If the packet being transmitted is equal to or less than the threshold,
fragmentation is not used.
Setting the threshold to the largest value (2,346 bytes) effectively disables
fragmentation. Fragmentation plays no role when Aggregation is enabled.
Fragmentation involves more overhead both because of the extra work of
dividing up and reassembling of frames it requires, and because it increases
message traffic on the network. However, fragmentation can help improve
network performance and reliability if properly configured.
Sending smaller frames (by using lower fragmentation threshold) might help
with some interference problems; for example, with microwave ovens.
By default, fragmentation is off. We recommend not using fragmentation
unless you suspect radio interference. The additional headers applied to
each fragment increase the overhead on the network and can greatly reduce
throughput.
• RTS Threshold—The Request to Send (RTS) Threshold value. The valid
integer range must be from 0 to 2347.
The RTS threshold indicates the number of octets in an MPDU, below which
an RTS/CTS handshake is not performed.
Changing the RTS threshold can help control traffic flow through the WAP
device, especially one with a lot of clients. If you specify a low threshold
value, RTS packets will be sent more frequently. This will consume more
bandwidth and reduce the throughput of the packet. On the other hand,
sending more RTS packets can help the network recover from interference
or collisions which might occur on a busy network, or on a network
experiencing electromagnetic interference.
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beacon.
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