Ch07: Local Area Networks: Part 1

10GBase-SR

a 10-gigabit Ethernet standard transmitted over fiber-optic cables for short-range distances

10GBase-CX4

a 10-gigabit Ethernet standard transmitted over specialized copper cables

10GBase-LR

a 10-gigabit Ethrnet standard transmitted over single-mode fiber-optic cables for long distances

local area network (LAN)

a communication network that interconnects a variety of data communicating devices within a small geographic area and broadcasts data at high data transfer rates with very low error rates

carrier sense multiple access with collision detection (CSMA/CD)

a contention-based medium access control protocol for bus and star-wired bus local area networks in which a workstation wanting to transmit can only do so if the medium is idle; otherwise, it has to wait. Signal collisions are detected by transmitting workstations, which then back off and retransmit

store-and-forward device

a device that accepts a packet, temporarily stores it in a buffer, decodes the packet as required by the device, and forwards the packet onto the next device

hub

a device that interconnects two or more workstations in a star-wired bus local area network and broadcasts incoming data onto all outgoing connections

switch

a device that is a combination of a hub and a bridge; it can interconnect multiple workstations (like a hub), but can also filter out frames, thereby providing a segmentation of the network (like a bridge)

contention-based protocol

a first-come, first-served protocol-the first station to recognize that no one is transmitting data is the first station to transmit

Power over Ethernet (PoE)

a form of Ethernet LAN in which the electrical power to operate the device is transmitted over the data cabling such that a separate connection to an electrical outlet is not necessary

file server

a high-powered workstation on a local area network that acts as a repository for user and network files, an is sometimes called a network server; a file server also holds all the files required by the network operating system

bidirectional

a kind of transmission in which a signal transmitted from a given workstation propagates in both directions on the cable away from the source

dedicated segment network

a local area network (or part of a local area network) in which a switch is used to interconnect two or more workstations. Since a hub is not involved, each workstation does not have to share the network capacity with other workstations

shared segment network

a local area network (or portion of a local area network) in which hubs interconnect multiple workstations. When one workstation transmits, all workstations hear the signal and thus all are sharing the bandwidth of the network segment

shared network

a local area network in which all workstations immediately hear a transmission

nondeterministic protocol

a local area network medium access control protocol in which you cannot calculate the time when a workstation will transmit

tap

a passive device that allows you to connect a coaxial cable to another continuous piece of coaxial cable

logical design

a process, or the final product, that maps how the data moves around a network from a workstation to workstation

Rapid Spanning Tree Protocol (RSTP)

a protocol that allows the switches within a local area network to virtually remove redundant paths between devices; a faster operating protocol than spanning tree protocol

passive device

a simple connection point between two runs of cable that does not regenerate the signal on the cable

logical link control (LLC) sublayer

a sublayer of the data link layer of the OSI model that is primarily responsible for logical addressing, and for providing error control and flow control information

backward learning

a technique in which a bridge or switch creates its routing tables by watching the current flow of traffic

virtual LAN

a technique in which various workstations on a local area network can be configured via software and switches to act as a private segment local area network

cut-through architecture

a technology in a LAN bridge or switch that allows the data frame to exit the switch almost as soon as it begins to enter the switch

full-duplex switch

a type of switch that allows for simultaneous transmission and reception of data to and from a workstation

1000BaseLX

an 802.3 standard, created by IEEE for Ethernet (or CSMA/CD local are networks), that incorporates 1000-Mbps baseband (digital) signaling for transmitting data over either single-mode or multimode fiber-optic cable that is being used to support longer-distance cabling within a single building

100BaseFX

an 802.3 standard, created by IEEE for Ethernet (or CSMA/CD local area network), that incorporates 100-Mbps baseband (digital) signaling for transmitting data over two-pair Category 5 twisted pair for a maximum segment length of 100 meters

10GBase-T

an 802.3 standard, created by IEEE for Ethernet (or CSMA/CD local area networks), that incorporates 10-Gbps baseband (digital) signaling for transmitting data over twisted pair

10Base5

an 802.3 standard, created by IEEE for Ethernet (or CSMA/CD local area networks), that incorporates 10-Mbps baseband (digital) signaling for transmitting data over coaxial cable for maximum segment length of 500 meters

10BaseT

an 802.3 standard, created by IEEE for Ethernet (or CSMA/CD local area networks), that incorporates 10-Mbps baseband (digital) signaling for transmitting data over twisted pair for a maximum segment length of 100 meters

10Broad36

an 802.3 standard, created by IEEE for Ethernet (or CSMA/CD local area networks), that incorporates 10-Mbps broadband (analog) signaling for transmitting data over coaxial cable for a maximum segment length of 3600 meters

100BaseT4

an 802.3 standard, created by IEEE for Ethernet (or CSMA/CD local area networks), that incorporates 100-Mbps baseband (digital) signaling for transmitting data over four pairs of Category 3 or higher twisted pair for a maximum segment length of 100 meters

100BaseTX

an 802.3 standard, created by IEEE for Ethernet (or CSMA/CD local area networks), that incorporates 100-Mbps baseband (digital) signaling for transmitting data over two paris of Category 5 or higher twisted pair for a maximum segment length of 100 meters

1000BaseT

an 802.3 standard, created by IEEE for Ethernet (or CSMA/CD local area networks), that incorporates 1000-Mbps baseband (digital) signaling for transmitting data over Category 5e or higher twisted pair (UTP) wire for a maximum segment length of 100 meters

1000BaseSX

an 802.3 standard, created by IEEE for Ethernet (or CSMA/CD local area networks), that incorporates 1000-Mbps baseband (digital) signaling for transmitting data over multimode fiber-optic cable that is being used to support relatively close clusters of workstations and devices

1000BaseCX

an 802.3 standard, created by IEEE for Ethernet (or CSMA/CD local area networks), that incorporates 1000-Mbps baseband (digital) signaling for transmitting data over short distances (in the 0.1-to-25-meter range) using copper jumper cables

Gigabit Ethernet

an Ethernet specification for transmitting data at 1 billion bits per second

Spanning Tree Protocol (STP)

an algorithm used by local area network switches that looks at all possible paths within a network and creates a tree structure that includes only unique paths between any two points. Switches use this algorithm to avoid sending data across redundant paths (loops) within a network. Replaced by Rapid Spanning Tree Protocol

network interface card (NIC)

an electronic device, typically in the form of a computer circuit board, that performs the necessary signal conversions and protocol operations so that the workstation can send and receive data on the network

filter

examines the destination address of a frame, and either forwards or does not forward the frame based on some address information stored within the bridge

runts

frames on a CSMA/CD local area network that are (probably due to a collision) shorter than 64 bytes

link aggregation

the ability to combine multiple connections between two devices within a local area network in order to increase data transfer rate. The term can also apply to telephone/data connections

hot swappable

the capability of removing a device from a computer workstation without turning off the power to the workstation

quality of service

the concept that data transmission rates, error rates, and other network traffic characteristics can be measured, improved, and (it is hoped) guaranteed in advance

Ethernet

the first commercially available local area network system (and currently the most popular). Almost identical in operation to CSMA/CD

bus/tree local area network

the first topology used when local area networks became commercially available in the late 1970s; it essentially consists of a single coaxial cable to which all workstations attach

10-Gbps Ethernet

the general term to represent 10-Gbps Ethernet local area networks

Fast Ethernet

the group of 100-Mbps Ethernet standards designated by the IEEE 802.3u protocol

collision window

the interval during which the signals in a CSMA/CD local area network propagate down the bus and back (the interval during which a collision can happen)

print server

the local area network software that allows multiple workstations to send their print jobs to a shared printer

backplane

the main hardware of a device (such as a LAN switch) into which all supporting printed circuit cards connect

trees

the more complex bus topologies consisting of multiple cable segments that are all interconnected

star-wired bus LAN

the most popular configuration for a local area network; a hub (or similar device) is the connection point for multiple workstations and may be connected to other hubs

100 GbE

the newest standard for Ethernet local area networks that supports 40-gigabit and 100-gigabit data transmissions. Also known as the IEEE 802.3ba standard

40 GbE

the newest standard for Ethernet local area networks that supports 40-gigabit and 100-gigabit data transmissions. Also known as the IEEE 802.3ba standard

physical design

the pattern formed by the locations of the elements of a network, as it would appear if drawn on a large sheet of paper

collision

the result of the signals from two or more devices colliding on a medium