Ender204426777乾颐堂CCNAv3.0课程InterconnectingCiscoNetworkingDevices,Part1(ICND1)v3.0BuildingaSimpleNetwork构建小型网络乾颐堂CCNAv3.0Ender204426777WhatIsaNetwork?Ender.ICND1—1-3Anetworkisaconnectedcollectionofdevicesthatcancommunicatewitheachother网络是一组通信设备的集合乾颐堂CCNAv3.0Ender204426777PhysicalComponentsofaNetworkEnder.ICND1—1-4乾颐堂CCNAv3.0Ender204426777InterpretingaNetworkDiagram-图解网络Ender.ICND1—1-5Therearefourmajorcategoriesofphysicalcomponentsinacomputernetwork:computers,interconnections,switches,androuters乾颐堂CCNAv3.0Ender204426777网络中的其他设备乾颐堂CCNAv3.0Ender204426777ImpactofUserApplicationsontheNetwork•Batchapplications:–FTP,TFTP,inventoryupdates–Nodirecthumaninteraction–Bandwidthimportant,butnotcritical•Interactiveapplications:–Inventoryinquiry,databaseupdate–Human-to-machineinteraction–Humanwaitingforresponse,responsetimeimportantbutnotcritical,unlesswaitbecomesexcessive•Real-timeapplications:–VoIP,video–Human-to-humaninteraction–End-to-endlatencycriticalEnder.ICND1—1-6乾颐堂CCNAv3.0Ender204426777CharacteristicsofaNetwork•Topology-拓扑•Speed-速度•Cost-开销•Security-安全性•Availability-可用性，衡量设备在投入使用后实际使用的效能，是设备或系统的可靠性、可维护性和维护支持性的综合特性•Scalability-扩展性•Reliability-可靠性，系统在一定时间内、在一定条件下无故障地执行指定功能的能力Ender.ICND1—1-7乾颐堂CCNAv3.0Ender204426777PhysicalTopologies•Physicallayoutofthedevicesandcabling•Threeprimarycategories(bus,star,andmesh)Ender.ICND1—1-8乾颐堂CCNAv3.0Ender204426777LogicalTopologiesLogicalpathsthatthesignalsusetotravelfromonepointonthenetworktoanother-逻辑链路是设备之间流量经过的路径Ender.ICND1—1-9乾颐堂CCNAv3.0Ender204426777Summary•Anetworkisaconnectedcollectionofdevicesthatcancommunicatewitheachother.•Therearefourmajorcategoriesofphysicalcomponentsinacomputernetwork:computers,interconnections,switches,androuters.•Iconsareusedtorepresentthecomponentsofanetworkinanetworkdiagram.•Commonnetworkuserapplicationscanbegroupedintobatch,interactive,andreal-timeapplications.•Thewaysinwhichnetworkscanbedescribedincludecharacteristicsthataddressnetworkperformanceandstructure:topology,speed,cost,security,availability,scalability,andreliability.•Aphysicaltopologydescribesthelayoutforwiringthephysicaldevices.Alogicaltopologydescribeshowinformationflowsthroughanetwork.Ender.ICND1—1-10
