Chapter 7 : LANS
Logical Design
A process, or the final product, that maps how the data moves around a network from workstation to workstation.
1000 Base T
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 wire for maximum segment length of 100 meters.
Gigabit Ethernet
An ethernet specification for transmitting data at 1 billion bits per second.
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 ther hubs.
Local Area Network LAN
A communication network that interconnects a variety of data communicating devices within a small geographic area and bradcasts 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; it has to wait. Signal collisions are detected by transmitting workstations, which then back off and retransmit.
Hub
A device that interconnects two or more workstations in a star-wired bus local area network and braodcasts incoming data onto all outgoing connections.
Switch
A device that is a combination of a hub and a bridge; it can interconnect multipleworkstation, like a hub, but can also filter out frames, thereby providing a segmentation of the network, like a bridge.
Contention-Based Protocols
A first-come, first-serve 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, and 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.
Shared Network
A local area network in which all workstation 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.
Dedicated Segment Network
A local area network, or part of one, 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 part of one, 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.
Tap
A passive device that allows you to connect a coaxial cable to another continuous piece of coaxial cable.
Round-Robin Protocols
A protocol in which each workstation takes a turn at transmission, and the turns are uniformly distributed over all workstations.
Medium Access Control Protocol
A protocol that allows a device, such as a workstation, to gain access to the medium, the transmission system, of a local area network.
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.
Medium Access Control, MAC, Sublayer
A sublayer formed from the splitting of the data link layer of the OSI model, MAC works closely with the physical layer and contains a header, computer's physical addresses error detection codes, and control information.
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, VLAN
A technique in which various workstation 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 the switch.
Full-Duplex Switch
A type of switch that allows for simultaneous transmission and reception of data to and from a workstation.
100 Base FX
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.
100 Base T4
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.
100 Base TX
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 pairs of Category 5 or higher twisted pair for a maximum segment length of 100 meters.
1000 Base LX
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 either single-mode or multimode fiber-optic cable that is being used to support longer-distance cabling within a single building.
1000 Base SX
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 workstation and devices.
1000 Base CX
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 calbes.
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 and two points. Switches use this algorithm to avoid sending data across redundant paths, within a network.
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.
Transparent
An interconection device designed for CSMA/CD LANs that observes network traffic flow and uses this information to make future decision regarding frame forwarding.
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.
Please Do Not Throw Sausage Pizza Away
Physical, Data Link, Network, Transport, Session, Presentation, Application
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.
Link Aggregation
The ability to combine multiple connections between two devices within a local area network in order to increase data transfer rate.
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, bus LAN
The first topology used when local area networks became commercially available in the late 1970's; it essentialy consists of a single coaxial cable to which all workstation 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 locas 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 sendtheir print jobs to a shared printer.
Backplane
The main hardware of a device, such as a LAN switch, into which all supporting printed circuits cards connect.
Trees
The more complex bus topologies consisting of multiple cable segments that are all interconnected.
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.
Topologies
The physical layout or configuration of a local area network or a wide area network.
Collision
The result of the signals from two or more devices colliding on a medium.
