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Glossary
Frame
The basic unit of Ethernet data traffic. An Ethernet frame can vary in size from
a minimum length of 64 bytes to a maximum length of 1522 bytes. An Ethernet
frame contains the Ethernet destination address, Ethernet source address,
802.1Q/1p fields, and TCP/IP packet.
Gigabit Ethernet
An extension of the Ethernet standard, offering speeds of 1 Gbps. That equals
1,000 Mbps —or 100 times the speed of standard Ethernet. See also Bandwidth,
Ethernet, and Fast Ethernet.
Hub
A device that interconnects clients and servers, simply repeating or amplifying the
signals between them. Hubs act as wiring "concentrators" in networks based on
star topologies, rather than bus topologies, in which computers are daisy-chained
together. See also Switch.
Inline Power
Inline power is 48-volt DC power delivered to terminal devices such as IP phones
over standard network cables, eliminating the need for separate power sources
such as wall outlets.
Internet
A massive global network, interconnecting countless computers and networks
worldwide. It is accessible from any computer with a modem or router connection
and the appropriate software.
IP
Internet Protocol. A network layer protocol in the TCP/IP stack offering a connec-
tionless internetwork service. IP provides features for addressing, type-of-service
specification, fragmentation and reassembly, and security.
IP Routing
Unlike static routing, where traffic patterns are established by the network admin-
istrator and must be manually adjusted, IP routing is dynamic. When a packet
begins its journey through the network, its entire route is not known. Instead,
it progresses through the network one "hop" at a time, and at each interval the
network automatically calculates the ideal route to the next stop along the way.
This improves network performance and availability.
IP Telephony
The transmission of voice and fax telephone calls over data networks using the
Internet Protocol.
IP Video
The transmission of video images over data networks using the Internet Protocol.
LAN
Local-area network. Typically, a network or group of network segments confined
to one building or a campus. See also WAN (Wide Area Network).
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