Encryption Type; Preamble Type - ZyXEL Communications ZyXEL Prestige 202 User Manual

2.3 Encryption Type

The IEEE 802.11b/g standard describes a simple encryption method between the wireless
stations and AP. Two encryption types are defined: an Open system mode and a Shared key
mode.
• Open system mode is implemented for ease-of-use and when security is not an issue.
The wireless station and the AP do not share a secret key. Thus the wireless stations can
associate with any AP and listen to any data transmitted plaintext.
• Shared key mode involves a shared secret key to authenticate the wireless station to the
AP. This requires you to enable the wireless LAN security and use same settings on both
the wireless station and the AP.

2.4 Preamble Type

Preamble is used to signal that data is coming to the receiver.
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 Long and Short to have the ZyXEL M-202 automatically use short preamble when
access point/wireless stations support it, otherwise the ZyXEL M-202 uses long preamble.
Note: The ZyXEL M-202 and the access point/wireless stations MUST use the same
preamble mode in order to communicate.
Chapter 2
ZyXEL M-202 User's Guide
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