Chapter 1. Before You Start
Air Live IAS-2000 User’s Manual V1.0
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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.
802.3ad
802.3ad is an IEEE standard for bonding or aggregating multiple Ethernet ports into one virtual interface (also
known as trunking). The aggregated ports appear as a single IP address to your computer and applications. This
means no application changes are required. The advantages of aggregation are that the virtual interface provides
increased bandwidth by merging the bandwidth of the individual ports. The TCP connection load is then balanced
across the ports. In addition to load balancing, 802.3ad provides automatic fail-over in the event any port or cable
fails. All traffic that was being routed over the failed port is automatically re-routed to use one of the remaining ports.
This fail-over is completely transparent to the application software using the connection.
Access Point
A device that allows wireless-equipped computers and other devices to communicate with a wired network. It is also
used to expand the range of a wireless network.
Bandwidth
The amount of transmission capacity that is available on a network at any point in time. Available bandwidth
