Icnd1 Chapter 3 Key Terms

Front 1

1000BASE-T

Back 1

A name for the IEEE Gigabit Ethernet standard that uses four-pair copper cabling, a speed of 1000Mbps (1Gbps) and a maximum cable length of 100m.

Front 2

100BASE-TX

Back 2

A name for the IEEE Fast Ethernet standard that uses two-pair copper cabling, a speed of 100Mbps and a maximum cable length of 100m.

Front 3

10BASE-T

Back 3

The 10Mbps baseband Ethernet specification using two pairs of twisted-pair cabling (Categories 3, 4 or 5): One pair transmits data and the other recieves data. 10BASE-T, which is part of the IEEE 802.3 specification, has a distance limit of approximately 100m per segment.

Front 4

Crossover Cable

Back 4

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 one the other end of the cable.

Front 5

CSMA/CD

Back 5

Carrier Sense Multiple Access Collision Detect. A media-access mechanism in which devices ready to transmit data first check the channel for a carrier. If no carrier is sensed for a specific period of time, a device can transmit. If two devices transmit at once, a collision occurs and is detected by all colliding devices. This collision subsequently delays retransmissions from those devices for a random length of time.

Front 6

Full-Duplex

Back 6

Generically, any communication in which two communicating devices can concurrently send and recieve data. In Ethernet LANs, the allowance for both devices to send and recieve at the same time, allowed when both devices disable their CSMA/CD logic.

Front 7

Half-Duplex

Back 7

Generically, any communication in which only one device at a time can send data. In Ethernet LANs, the normal result of the CSMA/CD algorithm that enforces the rule that only one device should send at any point in time.

Front 8

Hub

Back 8

A LAN device that provides a centralised connection point for LAN cabling, repeating any recieved electrical signal out all other ports, thereby creating a logical bus. Hubs do not interpret the electrical signals as a frame of bits, so hubs are considered to be layer 1 devices.

Front 9

Pinout

Back 9

The documentation and implementation of which wires inside a cable connect to each pin position in any connector.

Front 10

Protocol Type

Back 10

A field in a LAN header that identifies the type of header that follows the LAN header. Includes the DIX Ethernet Type Field, the IEE 802.2 DSAP field and the SNAP protocol type field.

Front 11

Shared Ethernet

Back 11

An Ethernet that uses a Hub, or even the original coaxial cabling, which results in devices having to take turns to send data, sharing the available bandwidth.

Front 12

Straight-Through Cable

Back 12

In Ethernet, a cable that connects the wire on Pin 1 on one end of the cable to Pin 1 on the other, Pin 2 to Pin2 and so on.

Front 13

Switch

Back 13

A network device that filters, forwards and floods Ethernet frames based on the destination address of each frame.

Front 14

Switched Ethernet

Back 14

An Ethernet that uses a switch, and particularly not a hub, so that the devices connected to one switch port do not have to contend to use bandwidthavailable on another port. This term contrasts with shared Ethernet, in which the devices must share bandwidth, whereas switched Ethernet provides much more capacity, as the devices do not have to share the available bandwidth.

Front 15

Twisted Pair

Back 15

Transmission medium consisting of two insulated wires, with the wires twisted around eachother in a spiral. An electrical circuit flows over the wire pair, with the current in opposite directions on each wire, which significantly reduces the interference between two wires.