User's Manual

Wireless Configuration
79
5
If the RTS threshold is set to 0, the access point always sends RTS signals. If set
to 2347, the access point never sends RTS signals. If set to any other value, and
the packet size equals or exceeds the RTS threshold, the RTS/CTS (Request to
Send / Clear to Send) mechanism will be enabled.
The access points contending for the medium may not be aware of each other. The
RTS/CTS mechanism can solve this “Hidden Node Problem.” (Range: 0-2346
bytes: Default: none)
• Fragmentation Threshold – Packet Fragmentation can also be used to improve
throughput in noisy/congested situations. Although packet fragmentation is often
thought of as something bad, and does add a large overhead, reducing throughput,
sometimes it is necessary. (Range: 256-2346)
WLAN Security
The unit’s wireless interface is configured by default as an “open system,” which
broadcasts a beacon signal including the configured SSID. Wireless clients with a
configured SSID of “ANY” can read the SSID from the beacon, and automatically set
their SSID to allow immediate connection to the wireless network.
To improve wireless network security, you have to implement two main functions:
• Authentication – It must be verified that clients attempting to connect to the network
are authorized users.
• Traffic Encryption – Data passing between the unit and clients must be protected
from interception and eavesdropping.
For a more secure network, the access point can implement one or a combination of
the following security mechanisms:
• Wired Equivalent Privacy (WEP)
• IEEE 802.1X
• Wi-Fi Protected Access (WPA) or WPA2
The security mechanisms that may be employed depend on the level of security
required, the network and management resources available, and the software
support provided on wireless clients.
WEP Security
WEP provides a basic level of security, preventing unauthorized access to the
network, and encrypting data transmitted between wireless clients and the access
point. WEP uses static shared keys (fixed-length hexadecimal or alphanumeric
strings) that are manually distributed to all clients that want to use the network.
WEP is the security protocol initially specified in the IEEE 802.11 standard for
wireless communications. Unfortunately, WEP has been found to be seriously
flawed and cannot be recommended for a high level of network security. For more
robust wireless security, the access point provides Wi-Fi Protected Access (WPA)
for improved data encryption and user authentication.