Fragmentation
A radio agenda or admission point can be set to optionally use fragmentation, which divides 802.11 data
frames into abate pieces (fragments) that are beatific alone to the destination. Anniversary fragment
consists of a MAC band header, anatomy analysis arrangement (FCS), and a fragment cardinal indicating
its ordered position aural the frame. Because the antecedent base transmits anniversary fragment
independently, the accepting base replies with a abstracted accepting for anniversary fragment.
An 802.11 base applies breach alone to frames accepting a unicast destination address. This
includes any abstracts anatomy directed against a specific station. To abbreviate aerial on the network,
802.11 does not fragment advertisement and multicast frames.
The destination base reassembles the bits into the aboriginal anatomy application fragment numbers.
After ensuring that the anatomy is complete, the base easily the anatomy up to college layers for
processing. Even admitting breach involves added overhead, its use can aftereffect in better
performance if you tune it properly.
Fragmentation can admission the believability of anatomy transmissions back cogent RF arrest is
present. Back transmitting abate frames, collisions are beneath acceptable to occur. In addition, frames that
do appointment errors can be retransmitted faster because they are smaller. The fragment admeasurement amount can
typically be set amid 256 and 2048 bytes, although this amount is user-configurable. In fact, you
activate breach by ambience a accurate anatomy admeasurement beginning (in bytes). If the anatomy that the access
point is transmitting is beyond than the beginning (similar to RTS/CTS), it will activate fragmentation. If
the packet admeasurement is according to or beneath than the threshold, the admission point will not use fragmentation.
Consider enabling breach on radio cards and admission points. As with configuring RTS/CTS,
first set the breach beginning to 750 bytes. If throughput increases, again breach is
beneficial. If throughput decreases, again breach apparently won’t be worthwhile. Because of
the added aerial appropriate for anatomy headers on anniversary fragment, the abridgement in frame
retransmissions ability not be abundant to annul the added aerial necessary.