User's Manual

Wireless Array
502 Glossary of Terms
VLAN
(Virtual LAN) A group of devices that communicate as a single network, even
though they are physically located on different LAN segments. Because VLANs
are based on logical rather than physical connections, they are extremely flexible.
A device that is moved to another location can remain on the same VLAN
without any hardware reconfiguration.
VLAN tagging
(Virtual LAN tagging) Static port-based VLANs were originally the only way to
segment a network without using routing, but these port-based VLANs could
only be implemented on a single switch (or switches) cabled together. Routing
was required to transfer traffic between unconnected switches. As an alternative
to routing, some vendors created proprietary schemes for sharing VLAN
information across switches. These methods would only operate on that vendor's
equipment and were not an acceptable way to implement VLANs. With the
adoption of the 802.11n standard, traffic can be confined to VLANs that exist on
multiple switches from different vendors. This interoperability and traffic
containment across different switches is the result of a switch's ability to use and
recognize 802.1Q tag headers called VLAN tagging. Switches that implement
802.1Q tagging add this tag header to the frame directly after the destination and
source MAC addresses. The tag header indicates:
1. That the packet has a tag.
2. Whether the packet should have priority over other packets.
3. Which VLAN it belongs to, so that the switch can forward or filter it
correctly.
WDS (Wireless Distribution System)
WDS creates wireless backhauls between arrays. These links between arrays may
be used rather than having to install data cabling to each array.
WEP
(Wired Equivalent Privacy) An optional IEEE 802.11 function that offers frame
transmission privacy similar to a wired network. The Wired Equivalent Privacy
generates secret shared encryption keys that both source and destination stations
can use to alter frame bits to avoid disclosure to eavesdroppers.