CCNA1_M2_Networking_Fundamentals (1130686)

Просмтор этого файла доступен только зарегистрированным пользователям. Но у нас супер быстрая регистрация: достаточно только электронной почты!

Текст из файла

CCNA – Semester1Module 2Networking FundamentalsObjectives••••Networking terminologySome network architecturesThe importance of bandwidthNetworking models: OSI vs TCP/IPNetworking TerminologyRelative size of networkNetworking Devices• Equipment that connects directly to a network segmentis referred to as a device.• There are 2 type of devices: end-user devices andnetwork devices.Network Devices• Repeater: regenerate a signal.• Hub: concentrate connections and mayregenerate a signal.• Bridge: convert network transmissiondata formats as well as perform basicdata transmission management.• Switch: add more intelligence to datatransfer management.• Router: routing and other servicesNetwork Topology• The physical topology, which is the actuallayout of the wire or media.• The logical topology, which defines how themedia is accessed by the hosts for sendingdata.Physical TopologyLogical TopologyBroadcastToken PassingLogical Topology: Broadcast• Each host sends its data to all other hosts onthe network medium.• First-come, first-serve.• Eg: EthernetLogical Topology: Token Passing• Access to media is controlled by an electronictoken.• Possession of the token gives the host the right topass data to its destination.• Eg: Token-Ring, FDDINetwork Protocols• Protocol suites are collections of protocolsthat enable network communication from onehost through the network to another host.• A protocol is a formal description of a set ofrules and conventions that govern a particularaspect of how devices on a networkcommunicate.Functions of Protocols• Protocols control all aspects of datacommunication, which include the following:–––––How the physical network is builtHow computers connect to the networkHow the data is formatted for transmissionHow that data is sentHow to deal with errorsLANs• Operate within a limited geographic area• Allow many users to access high-bandwidthmedia• Provide full-time connectivity to local services• Connect physically adjacent devicesLAN Devices and Technology• Some common LAN technologies are:– Ethernet– Token Ring– FDDIWANs• Operate over a large geographically separated areas• Provide full-time remote resources connected to localservicesWAN Technologies Include• Some common WAN technologies are:–––––––Analog modemsIntegrated Services Digital Network (ISDN)Digital Subscriber Line (DSL)Frame RelayAsynchronous Transfer Mode (ATM)T (US) and E (Europe) carrier series: T1, E1, T3, E3Synchronous Optical Network (SONET)Metropolitan-Area Networks (MANs)• A MAN is anetwork that spansa metropolitanarea such as a cityor suburban area.• A MAN usuallyconsists of two ormore LANs in acommongeographic area.Storage-Area Networks (SANs)• A SAN is a dedicated,high-performancenetwork used to movedata between serversand storage resources.Virtual Private Networks (VPNs)• A VPN is a privatenetwork that isconstructed within apublic networkinfrastructure such asthe global Internet .• VPN is the most costeffective method ofestablishing securedconnectionVPN TypesThere are three main types of VPNs:•••Access VPNsIntranet VPNsExtranet VPNsBandwidthImportance of BandwidthDigital Bandwidth• Bandwidth is the measure of how muchinformation, or bits, can flow from one place toanother in a given amount of time, or seconds.Bandwidth Limitations (LAN)Bandwidth Limitations (WAN)Throughput• Throughput refers to actual measuredbandwidth, at a specific time of day, usingspecific Internet routes, and while a specificset of data is transmitted on the network.• Factors that determine throughput:–––––––Internetworking devicesType of data being transferredNetwork topologyNumber of users on the networkUser computerServer computerPower conditionsData Transfer CalculationCalculate an estimate of network performanceNetworking ModelsAnalyzing network in layerWhatWhat isis flowingflowing ??DataDataWhatWhat differentdifferent formsforms flowflow ??Text,Text, Graphic,Graphic, VideoVideo ......WhatWhat rulesrules governgovern flowflow ??Standard,Standard, ProtocolProtocol ......WhereWhere doesdoes thethe flowflow occuroccur ??Cable,Cable, AtmosphereAtmosphere ......Communication characteristics• Addresses– What are the source and the destination of a communicationprocess?• Media– Where does the communication take place?• Protocols– How to make the communication process effectively?PacketsProtocolsSourceAddressMediumDestinationAddressData Communication• Address– Source address, Destination address• Media– Cable, Fiber, Atmosphere• Protocol– Format– ProcedureEvolution of networking standardsSNAStandard• Interconnection• Development• SimplificationProprietaryTCP/IPDECNETOSI Model• The OSI model:model a framework within whichnetworking standards can be developed.– It provided vendors with a set of standards thatensured greater compatibility and interoperabilitybetween the various types of network technologiesthat were produced by the many companies aroundthe world.Proprietary vs.

OpenWhy a layered model••••Reduces complexity.Standardizes interfaces.Facilitates modular engineering.Ensures technologycompatibility.• Accelerates evolution.• Simplifies teaching andlearning.7 layers of the OSI reference modelNetwork processes to applicationsData representationInterhost communicationEnd-to-end connectionsAddress and best pathDirect link control, accessto mediaaBinary transmission•All People Seem To Need Data Processing7 layers of the OSI reference modelNetwork processes to applications• Is the OSI layer that is closest tothe user; it provides networkservices to the user’sapplications.––––File transferElectronic mailTerminal access…7 layers of the OSI reference modelData representation• Ensures that the information thatthe application layer of onesystem sends out is readable bythe application layer of anothersystem.––––Format of dataData conversionData compressionData encryption7 layers of the OSI reference modelInterhost communication• Establishes, manages, andterminates sessions betweentwo communicating hosts.––––SessionsDialogConversationsData exchange7 layers of the OSI reference modelEnd-to-end connections• Provides reliable, transparenttransfer of data over networks.–––––Segments, data stream, datagramEnd-to-end flow controlError detection and recoverySegmentation & reassembly…7 layers of the OSI reference modelAddress and best path• Provides connectivity andpath selection between twohost systems that may belocated on geographicallyseparated networks.–––––PacketsRoute, routing table,Logical addressFragmentation…7 layers of the OSI reference modelDirect link control, access to media• Provides for the reliable transferof data cross a physical link.–––––FramesPhysical addressNetwork topologyLine discipline…7 layers of the OSI reference modelBinary transmission• Transmission of anunstructured bit streamover a physical linkbetween end systems.– Electrical, mechanical, procedural andfunctional specifications– Physical data rate– Distances– Physical connector7 layers of the OSI reference modelNetwork processes to applicationsData representationInterhost communicationEnd-to-end connectionsAddress and best pathDirect link control, accessto mediaaBinary transmission•All People Seem To Need Data ProcessingPeer-to-Peer Communication• The protocols of eachlayer exchangeinformation, calledprotocol data units(PDUs), between peerlayers.EncapsulationThe lower layers useencapsulation to putthe protocol dataunit (PDU) from theupper layer into itsdata field and to addheaders and trailersthat the layer canuse to perform itsfunction.De-Encapsulation• When the data link layer receives the frame, itdoes the following:– It reads the physical address and other control information providedby the directly connected peer data link layer.– It strips the control information from the frame, thereby creating adatagram.– It passes the datagram up to the next layer, following theinstructions that appeared in the control portion of the frame.Encapsulation example: E-mailLayer-to-layer communicationsProvide servicesRequest servicesTCP/IP model development• The late-60s The Defense AdvanceResearch Projects Agency (DARPA)originally developed Transmission ControlProtocol/Internet Protocol (TCP/IP) tointerconnect various defense departmentcomputer networks.• The Internet, an International Wide AreaNetwork, uses TCP/IP to connect networksacross the world.The TCP/IP Reference Model••••Layer 4:Layer 3:Layer 2:Layer 1:It is important to note that some of thelayers in the TCP/IP model have the samename as layers in the OSI model.Do not confuse the layers of the two models.TCP/IP Protocol StackOSI Model and TCP/IP ModelFocus of the CCNA CurriculumSummary•••••••Networking devicesSome of the common network typesIntranet and extranetBandwidth and throughputThe layered communication modelOSI reference modelTCP/IP networking model.

Характеристики

Тип файла PDF

PDF-формат наиболее широко используется для просмотра любого типа файлов на любом устройстве. В него можно сохранить документ, таблицы, презентацию, текст, чертежи, вычисления, графики и всё остальное, что можно показать на экране любого устройства. Именно его лучше всего использовать для печати.

Например, если Вам нужно распечатать чертёж из автокада, Вы сохраните чертёж на флешку, но будет ли автокад в пункте печати? А если будет, то нужная версия с нужными библиотеками? Именно для этого и нужен формат PDF - в нём точно будет показано верно вне зависимости от того, в какой программе создали PDF-файл и есть ли нужная программа для его просмотра.

Список файлов учебной работы