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Appendix E - Glossary
10.
802.11 standard
A family of wireless Local Area Network specifications. The 802.11b standard in particular is seeing widespread
acceptance and deployment in corporate campuses as well as commercial facilities such as airports and coffee
shops that want to offer wireless networking service to their patrons.
802.11a
An IEEE specification for wireless networking that operates in the 5 GHz frequency range (5.725 GHz to 5.850 GHz)
with a maximum of 54 Mbps data transfer rate. The 5 GHz frequency band is not as crowded as the 2.4 GHz
frequency, because the 802.11a specification offers more radio channels than the 802.11b. These additional
channels can help avoid radio and microwave interference.
802.11b
International standard for wireless networking that operates in the 2.4 GHz frequency range (2.4 GHz to 2.4835 GHz)
and provides a throughput up to 11 Mbps. This is a very commonly used frequency. Microwave ovens, cordless
phones, medical and scientific equipment, as well as Bluetooth devices, all work within the 2.4 GHz frequency band.
802.11g
Similar to 802.11b, but this standard provides a throughput up to 54 Mbps. It also operates in the 2.4 GHz frequency
band but uses a different radio technology in order to boost overall bandwidth.
VLAN
Defines changes to Ethernet frames that will enable them to carry VLAN information. It allows switches to assign
end-stations to different virtual LANs, and defines a standard way for VLANs to communicate across switched
networks.
Four bytes have been added to the Ethernet frame for this purpose, causing the maximum Ethernet frame length to
increase from 1518 to 1522 bytes. In these 4 bytes, 3 bits allow for up to eight priority levels and 12 bits identify one
of 4,094 different VLANs. 802.3ac will define the specifics of these changes for Ethernet frames.
802.1x
802.1x is a security standard for wired and wireless LANs. It encapsulates EAP processes into Ethernet packets
instead of using the protocol's native PPP (Point-to-Point Protocol) environment, thus reducing some network
overhead. It also puts the bulk of the processing burden upon the client (called a supplicant in 802.1x parlance) and
the authentication server (such as a RADIUS), letting the "authenticator" middleman simply pass the packets back
and forth. Because the authenticator does so little, its role can be filled by a device with minimal processing power,
such as an access point on a wireless network.
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