Basic Network Management - Chapter 4: LAN Terminology and Components

Chapter 4: LAN TERMINOLOGY and COMPONENTSObjectiveLAN TerminologyLAN transmission media LAN technology and topology LAN networking devices LAN TerminologyLAN TerminologyLAN Transmission MediaWhat types of transmission should be used to connect LAN components?LAN TopologyWhat will be the shape or topology, that defines the LAN?Transmission MediaTransmission media refers to the type of cable or wireless system that is used to connect network devices:Coaxial CableTwisted PairUnshielded twisted-pairShielded twisted-pairFiber Optic CableTransmission MediaCoaxial CableCoaxial cable consists of central copper wire surrounded by two layer of protective shieldingInexpensive, light, flexible and easy to work More resistance to Electromagnetic Interference (EMI) and attenuationCoaxial Cable (2)Attenuation: loss of signal strength along wireCoaxial Cable (3)Types of Coaxial Cable The two basic classifications for coaxial cable are as follows:ThinnetThicknetThinnetThinnet is a flexible cabling medium that is inexpensive and easy to installThinnet is approximately 0.25 inches (0.5cm)Thinnet can transmit a signal for 185 meters (610 feet)ThicknetThicknet coaxial cable is approximately 0.5 inches (1.3cm)Thicknet can transmit approximately 500 meters (1650 feet)Copper core thicker than Thinnet coreThicknet (2)Connection HardwareThe most common is the British Naval Connector (BNC):BNC cable connectorBNC T-connectorBNC barrel connectorBNC terminatorConnection Hardware (2)BNC cable connectorConnection Hardware (3)BNC T-connector: connects the network interface card in the PC to the network cableConnection Hardware (4)BNC barrel connector: connects two thinnet cable segments into longer segmentConnection Hardware (5)BNC terminator: closes end cable to stop signalTwisted PairTwo-insulated strands of copper wire twisted around each otherThere are 2 categories of twisted pair: Shielded twisted pair (STP)Unshielded twisted pair (UTP)Twisted PairSTPUTPSTP CableShielded Twisted Pair (STP) includes a layer of shielding that protects the wires from electromagnetic interferenceSTPUTP CableUnshielded Twisted Pair (UTP)Max length segment: 100 meters (328 feet)Consists of two insulated copper wiresSpecified in 586 Commercial Building Wiring Standard by Electronic Industries Association and the Telecommunications Industries Association (EIA/TIA) UTP Cable (4)Susceptible to crosstalk:Signal overflow from adjacent wire Twisted Pair ComponentsThe most common connector used with UTP cable is RJ-45The RJ-45 resembles a phone plug RJ-11 except that the RJ-45 has 8 wires and 8 pinsDistribution RacksGood way to centralize connectionsTwisted Pair Components (2)RJ-45 Connector and Jack:Twisted Pair Components (4)Distribution rackTwisted Pair Components (3)Expandable patch panelsJack couplers Snap into patch panels and supports 100Mbps Wall PlatesSupport 2 or more couplersFiber Optic CableFiber-optic cable is designed to transmit digital data signals in the form of modulated pulses of light Cannot be tapped into and data stolenGood for high speed and high capacity data transmission Attenuation not a problemHigh purity of signalFiber Optic Cable (2)Fiber Optic Cable (3)Fiber-optic cable are cost and installation difficultyCan carry signal for miles Typical speed: 100Mbps (support high data rate 200000 Mbps) ConstructionCore : thin cylinder of glass can be plastic but signal does not travel as far Fiber Optic Cable (4)Cladding: concentric layer of glass which surrounds coreEach glass strand passes signal in one directionCable consists of strands in separate jackets: one transmit one receiveFiber Optic Cable Fiber Optic Cable LAN TopologyTopology Arrangement or physical layout of computersAlso known as :Physical layoutDesignDiagramMap LAN Topology (2)Two categories form:Physical topologyDescribes the actual layout of the network transmission mediaLogical topologyDescribes the logical pathway a signal follows as it passes among the network nodesLAN Bus TopologyLAN Bus Topology (2)Linear bus Simplest and most common Consists of a single cable called a trunk or backboneCommunication on the busAddress data to a particular computer and put data on cable in form of signals LAN Bus Topology (3)Sending the signal:Electronic signals sent to all computers on networkOne computer at a time can send a signal Bus is the passive topology: Computers listen for data being sent. If one computer fails, it does not effect the rest of the network In active topology: Computers regenerate signal and pass it on networkLAN Bus Topology (4)Signal bounce: When signal gets to end of cable and bounces back Terminator: Stops signal from bouncingLAN Bus Topology (5)Disrupting Network Connection:Segment breaks or disconnect to terminator, signal bounce occurs PC on the network can work but they could not communicate togetherLAN Expansion: Barrel connector can connect 2 cable segmentsUsing repeater to connect 2 cable segmentsLAN Bus Topology (6)Segment breakLAN Star Topology LAN Star Topology (2)Computers connected to centralized unit called a hub Signal transmitted to hub to all computers on network Offers centralized resources & management Central point fails, entire network goes downLAN Star Topology (3)Ethernet Media OptionsInclude:10Base210Base510Base-T10Base-FL100Base-X LAN networking devicesNetwork Adapter CardRepeater & HubSwitchRouter Network Adapter CardRole of Network Adapter Card: A Network Adapter Card ( also known as Network Interface Card ) links a computer with the network cabling systemPrepare data from computer to networkSend data to other computersControl flow of data between computer and cabling systemRepeaterEnables signal to travel farther (regenerates) and then re-transmitting it to other segmentsRepeaters operate at the OSI Physical LayerHubA hub is another Layer 1 device that is typically used as a central point for connecting segments in a LANSwitchMore common way to connect networks together RouterWork at Network layer of OSI, which means they examine the logical network address (192.168.15.100)SummaryThis topic examined :Provided to the basic terminology of LANDisplay Transmission Media and Components of LANLAN TopologyLAN Networking Devices