ZyXEL Communications NWA-1100, Руководство пользователя

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Appendix E Wireless LANs
ZyXEL NWA-1100 User’s Guide
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network overhead involved in the RTS (Request To Send)/CTS (Clear to Send)
handshake.
If the RTS/CTS value is greater than the Fragmentation Threshold value (see
next), then the RTS (Request To Send)/CTS (Clear to Send) handshake will never
occur as data frames will be fragmented before they reach
RTS/CTS size.
Note: Enabling the RTS Threshold causes redundant network overhead that could
negatively affect the throughput performance instead of providing a remedy.
Fragmentation Threshold
A Fragmentation Threshold is the maximum data fragment size (between 256
and 2432 bytes) that can be sent in the wireless network before the AP will
fragment the packet into smaller data frames.
A large Fragmentation Threshold is recommended for networks not prone to
interference while you should set a smaller threshold for busy networks or
networks that are prone to interference.
If the Fragmentation Threshold value is smaller than the RTS/CTS value (see
previously) you set then the RTS (Request To Send)/CTS (Clear to Send)
handshake will never occur as data frames will be fragmented before they reach
RTS/CTS size.
Preamble Type
Preamble is used to signal that data is coming to the receiver. Short and Long
refer to the length of the synchronization field in a packet.
Short preamble increases performance as less time sending preamble means
more time for sending data. All IEEE 802.11b/g compliant wireless adapters
support long preamble, but not all support short preamble.
Select Long preamble if you are unsure what preamble mode the wireless
adapters support, and to provide more reliable communications in busy wireless
networks.
Select Dynamic to have the AP automatically use short preamble when wireless
adapters support it, otherwise the AP uses long preamble.
Note: The AP and the wireless adapters MUST use the same preamble mode in order
to communicate.