User guide

U
Summit WM20 User Guide, Software Release 4.2 233
U
UDP User Datagram Protocol. A connectionless protocol that, like TCP,
runs on top of IP networks. Unlike TCP/IP, UDP/IP provides very
few error recovery services, offering instead a direct way to send and
receive packets over an IP network. It is used primarily for
broadcasting messages over a network.
U-NII Unlicensed National Information Infrastructure. Designated to provide
short-range, high-speed wireless networking communication at low
cost, U-NII consists of three frequency bands of 100 MHz each in the 5
GHz band: 5.15-5.25GHz (for indoor use only), 5.25-5.35 GHz and
5.725-5.825GHz. The three frequency bands were set aside by the FCC
in 1997 initially to help schools connect to the Internet without the
need for hard wiring. U-NII devices do not require licensing.
URL Uniform Resource Locator. the unique global address of resources or
files on the World Wide Web. The URL contains the name of the
protocol to be used to access the file resource, the IP address or the
domain name of the computer where the resource is located, and a
pathname -- a hierarchical description that specifies the location of a
file in that computer.
V
VLAN Virtual Local Area Network. A network of computers that behave as if
they are connected to the same wire when they may be physically
located on different segments of a LAN. VLANs are configured
through software rather than hardware, which makes them extremely
flexible. When a computer is physically moved to another location, it
can stay on the same VLAN without any hardware reconfiguration.
The standard is defined in IEEE 802.1Q - Virtual LANs, which states
that "IEEE 802 Local Area Networks (LANs) of all types may be
connected together with Media Access Control (MAC) Bridges, as
specified in ISO/IEC 15802-3. This standard defines the operation of
Virtual LAN (VLAN) Bridges that permit the definition, operation and
administration of Virtual LAN topologies within a Bridged LAN
infrastructure."
WM-AD WM Access Domain Services (WM-AD). A Extreme Networks specific
technique that provides a means of mapping wireless networks to a
wired topology.
VoIP Voice Over Internet Protocol. An internet telephony technique. With
VoIP, a voice transmission is cut into multiple packets, takes the most
efficient path along the Internet and is reassembled when it reaches
the destination.
VPN Virtual Private Network. A private network that is constructed by
using public wires to connect nodes. These systems use encryption
and other security mechanisms to ensure that only authorized users
can access the network and that the data cannot be intercepted.