Avaya W310 User Manual page 238

Chapter 12 W310 WLAN Gateway Wireless Features
Parameter
Fragmentation Threshold
212
Description
The 802.11 standard includes the ability for radio-based
network interface cards (NICs) and APs to fragment
packets for improving performance in the presence of RF
interference and marginal coverage areas.
A radio card or AP uses fragmentation to divide 802.11
frames into smaller pieces (fragments) that are sent
separately to the destination. Each fragment consists of
• MAC Layer header,
• frame check sequence (FCS), and a
• fragment number indicating its ordered position
within the frame.
The radio card or AP will transmit each fragment
independently so that the receiving station replies with a
separate acknowledgement for each fragment. An 802.11
station only applies fragmentation to frames having a
unicast receiver address. This includes any frame (for
example, data frame) directed toward a specific station.
In order to minimize overhead on the network, 802.11
does not fragment broadcast (for example, beacons) and
multicast frames.
The use of fragmentation can increase the reliability of
frame transmissions. When sending smaller frames,
collisions are much less likely to occur. The fragment
size value can be set between 256 and 2,346 bytes
(default). Setting the threshold to the largest value (2,346
bytes) effectively disables fragmentation.
Continued
Avaya W310 User's Guide