IronPort Systems ZyAIR B-4000 - Manual (Page 161)

ZyAIR B-4000 Hot Spot Gateway
Wireless LAN 18-5
Enabling the RTS Threshold causes redundant network overhead that could
negatively affect the throughput performance instead of providing a remedy.
18.2.4 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 ZyAIR 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.
18.2.5 Preamble Type
A preamble is a signal used to synchronize the transmission timing in your wireless network. There are two
preamble modes: Long and Short.
Long preamble mode allows more processing time for each transmitted data packet. Short preamble mode
allows less processing time for the transmitted data packets.
Using short preamble mode may minimize overhead and maximize network throughput. However, short
preamble mode is supported by IEEE 802.11b compliant wireless devices, thus wireless stations using short
preamble mode cannot communicate with wireless stations using the original IEEE 802.11 standard.
18.3 Wireless LAN Setup
If you are configuring the ZyAIR from a computer connected to the wireless LAN
and you change the ZyAIR’s ESSID or WEP settings, you will lose your wireless
connection when you press Apply to confirm. You must then change the wireless
settings of your computer to match the ZyAIR’s new settings.
Click ADVANCED SETUP and then WIRELESS to open the Wireless screen.