EtherFast
®
8-Port and 12-Port Gigabit Ethernet Switches
13
Instant EtherFast
®
Series
12
Hub - The device that serves as the central location for attaching wires from
workstations. Can be passive, where there is no amplication of the signals; or
active, where the hubs are used like repeaters to provide an extension of the
cable that connects to a workstation.
IEEE - The Institute of Electrical and Electronics Engineers. The IEEE
describes itself as “the world’s largest technical professional society – promot-
ing the development and application of electrotechnology and allied sciences
for the benefit of humanity, the advancement of the profession, and the well-
being of our members.”
The IEEE fosters the development of standards that often become national and
international standards. The organization publishes a number of journals, has
many local chapters, and several large societies in special areas, such as the
IEEE Computer Society.
LAN - A local area network (LAN) is a group of computers and associated
devices that share a common communications line and typically share the
resources of a single processor or server within a small geographic area (for
example, within an office building).
Latency - The time delay between when the first bit of a packet is received and
the last bit is forwarded.
MAC (Media Access Control) Address - A unique number assigned by the
manufacturer to any Ethernet networking device, such as a network adapter,
that allows the network to identify it at the hardware level.
Mbps (Megabits Per Second) - One million bits per second; unit of measure-
ment for data transmission.
MDI (Medium Dependent Interface) - On a network hub or switch, a MDI
port, also known as an uplink port, connects to another hub or switch using a
straight-through cable. To connect a MDI port to a computer, use a crossover
cable.
MDIX (Medium Dependent Interface Crossed) - On a network hub or switch,
a MDIX port connects to a computer using a straight-through cable. To connect
a MDIX port to another hub or switch, use a crossover cable.
Network - A system that transmits any combination of voice, video and/or data
between users.
CAT 5 - ANSI/EIA (American National Standards Institute/Electronic
Industries Association) Standard 568 is one of several standards that specify
“categories” (the singular is commonly referred to as “CAT”) of twisted pair
cabling systems (wires, junctions, and connectors) in terms of the data rates
that they can sustain. CAT 5 cable has a maximum throughput of 100 Mbps
and is usually utilized for 100BaseTX networks.
CAT 5e - The additional cabling performance parameters of return loss and far-
end crosstalk (FEXT) specified for 1000BASE-T and not specified for
10BASE-T and 100BASE-TX are related to differences in the signaling imple-
mentation. 10BASE-T and 100BASE-TX signaling is unidirectional-signals
are transmitted in one direction on a single wire pair. In contrast, Gigabit
Ethernet is bi-directional-signals are transmitted simultaneously in both direc-
tions on the same wire pair; that is, both the transmit and receive pair occupy
the same wire pair .
Data Packet - One frame in a packet-switched message. Most data communi-
cations is based on dividing the transmitted message into packets. For example,
an Ethernet packet can be from 64 to 1518 bytes in length.
Dynamic Routing - The ability for a router to forward data via a different route
based on the current conditions of the communications circuits. For example, it
can adjust for overloaded traffic or failing lines and is much more flexible than
static routing, which uses a fixed forwarding path.
Ethernet - IEEE standard network protocol that specifies how data is placed on
and retrieved from a common transmission medium. Has a transfer rate of 10
Mbps. Forms the underlying transport vehicle used by several upper-level proto-
cols, including TCP/IP and XNS.
Fast Ethernet - A 100 Mbps technology based on the 10BASE-T Ethernet
CSMA/CD network access method.
Full Duplex - The ability of a device or line to transmit data simultaneously in
both directions.
Half Duplex - Data transmission that can occur in two directions over a single
line, but only one direction at a time.
Hardware - Hardware is the physical aspect of computers, telecommunications,
and other information technology devices. The term arose as a way to distinguish
the “box” and the electronic circuitry and components of a computer from the pro-
gram you put in it to make it do things. The program came to be known as the soft-
ware.
