Ch. 2: Fundamentals of Ethrnet LANs Flashcards
Ethernet
A series of LAN standards defined by the IEEE, originally invented by Xerox Corporation and developed jointly by Xerox, Intel, and Digital Equipment Corporation.
IEEE
Institute of Electrical and Electronics Engineers. A professional organization that develops communications and network standards, among other activities.
wired LAN
A local-area network (LAN) that physically transmits bits using cables, often the wires inside cables. A term for local-area networks that use cables, emphasizing the fact that the LAN transmits data using wires (in cables) instead of wireless radio waves.
Ethernet frame
A term referring to an Ethernet data-link header and trailer, plus the data encapsulated between the header and trailer.
10BASE-T
The 10-Mbps baseband Ethernet specification using two pairs of twisted-pair cabling (Categories 3, 4, or 5): one pair transmits data and the other receives data. 10BASE-T, which is part of the IEEE 802.3 specification, has a distance limit of approximately 100 m (328 feet) per segment.
100BASE-T
A name for the IEEE Fast Ethernet standard that uses two-pair copper cabling, a speed of 100 Mbps, and a maximum cable length of 100 meters.
1000BASE-T
A name for the IEEE Gigabit Ethernet standard that uses four-pair copper cabling, a speed of 1000 Mbps (1 Gbps), and a maximum cable length of 100 meters.
Fast Ethernet
The common name for all the IEEE standards that send data at 100 megabits per second.
Gigabit Ethernet
The common name for all the IEEE standards that send data at 1 gigabit per second.
Ethernet link
A generic term for any physical link between two Ethernet nodes, no matter what type of cabling is used.
RJ-45
A popular type of cabling connector used for Ethernet cabling. It is similar to the RJ-11 connector used for telephone wiring in homes in the United States. It allows the connection of eight wires.
Ethernet port
A generic term for the opening on the side of any Ethernet node, typically in an Ethernet NIC or LAN switch, into which an Ethernet cable can be connected.
network interface card (NIC)
A computer card, sometimes an expansion card and sometimes integrated into the motherboard of the computer, that provides the electronics and other functions to connect to a computer network. Today, most are specifically Ethernet, and most have an RJ-45 port, the most common type of Ethernet port.
straight-through cable
In Ethernet, a cable that connects the wire on pin 1 on one end of the cable to pin 1 on the other end of the cable, pin 2 on one end to pin 2 on the other end, and so on.
crossover cable
An Ethernet cable that swaps the pair used for transmission on one device to a pair used for receiving on the device on the opposite end of the cable. In 10BASE-T and 100BASE-TX networks, this cable swaps the pair at pins 1,2 to pins 3,6 on the other end of the cable, and the pair at pins 3,6 to pins 1,2 as well.
Ethernet address
A 48-bit (6-byte) binary number, usually written as a 12-digit hexadecimal number, used to identify Ethernet nodes in an Ethernet network. Ethernet frame headers list a destination and source address field, used by the Ethernet devices to deliver Ethernet frames to the correct destination.
MAC address
A standardized data-link layer address that is required for every device that connects to a LAN. Ethernet MAC addresses are 6 bytes long and are controlled by the IEEE. Also known as a hardware address, a MAC layer address, and a physical address.
unicast address
Generally, any address in networking that represents a single device or interface, instead of a group of addresses (as would be represented by a multicast or broadcast address).
broadcast address
Generally, any address that represents all devices, and can be used to send one message to all devices.
Frame Check Sequence
A field in many data-link trailers used as part of the error-detection process.
transceiver
A term formed from the words transmitter and receiver. The hardware used to both send (transmit) energy over some communications medium (e.g., wires in a cable), as well as to process received energy signals to interpret as a series of 1s and 0s.
multimode fiber
A type of fiber cable that works well with transmitters like LEDs that emit multiple angles of light into the core of the cable; to accommodate the multiple angles of incident, the cable has a larger core in comparison to single-mode fiber cables.
single-mode fiber
A type of fiber cable that works well with transmitters like lasers that emit a single angle of light into the core of the cable, allowing for a smaller core in comparison to multimode fiber cables.
electromagnetic interference (EMI)
The name of the effect in which electricity passes through one cable as normal, inducing a magnetic field outside the conductor. That magnetic field, if it passes through another conductor, like a nearby cable, induces new electrical current in the second cable, interfering with the use of electricity to transmit data on the second cable.
core
In fiber-optic cabling, the center cylinder of the cable, made of fiberglass, through which light passes.
cladding
In fiber-optic cabling, the second layer of the cable, surrounding the core of the cable, with the property of reflecting light back into the core.
fiber-optic cable
A type of cabling that uses glass fiber as a medium through which to transmit light.
