Architecture EECS 1221Network ArchitectureIntroductionLayering ExampleInternet Layers – First LookLayering Step by StepDownside of LayeringInterconnecting NetworksThe InternetTOC – ArchitectureIntroduction Issues:Inter-operabilityExtensibilityApplications & TechnologiesScalabilityInternet Solution:Layered ArchitectureEnd-to-End PrincipleHierachical Addressing & NamingTOC – Architecture IntroductionLayer: Example…TOC – Architecture – Layer Example FAX SYSTEMSECRETARYJohnSECRETARYMaryProf. A Prof. BPlease fax letterto Prof. B, UrgentHere is a letter from Prof. AHere is my review of paper 554.I believe its main result is wrong.Here is a counterexample.Here is my review of paper 554.I believe its main result is wrong.Here is a counterexample.COVERTo: Prof. BFr: Prof. AUrgentHere is my review of paper 554.I believe its main result is wrong.Here is a counterexample.COVERTo: Prof. BFr: Prof. AUrgentLayer: Example…TOC – Architecture – Layer Example FAX SYSTEMSECRETARYJohnSECRETARYMaryProf. A Prof. BPlease fax letterto Prof. B, UrgentHere is a letter from Prof. AINTERFACEFUNCTIONSHEADERSERVICE - SECYSERVICE - FAXHere is my review of paper 554.I believe its main result is wrong.Here is a counterexample.Layer: ExampleTOC – Architecture Layer ExampleFAX SYSTEMSECRETARYJohnSECRETARYMaryProf. A Prof. B• Secretaries implement functions that transform a simple service into a more complex one(E.g., add MULTIPLEXING)• They follow rules of communication:PROTOCOL• They use the header as control information•Note: Encapsulation (adding header) and Decapsulation(removing header)Here is my review of paper 554.I believe its main result is wrong.Here is a counterexample.Here is my review of paper 554.I believe its main result is wrong.Here is a counterexample.COVERTo: Prof. BFr: Prof. AUrgentInternet Layers - IntroTOC – Architecture – Internet Layers: Intro BrowsingServicesNamesExamplesSpecificationsEncapsulationFunctionsArchitecture EECS 1222BrowsingName IP Address Connect; Get; Close Supervise ConnectionForward Packets Across Many LinksTransmit Packets on Each LinkTransmit Bits on Each MediumTOC – Architecture – Internet Layers: Intro Browsing 12345H HR R DSN Servers End hosts 5 End hosts 4 Routers 3 Link/LAN 2 Transceivers 1ServicesTOC – Architecture – Internet Layers: Intro Services 12345SignalsBitsPackets: End to EndConnectionApplicationPacketsNamesTOC – Architecture – Internet Layers: Intro Names 12345SignalsBitsPackets: End to EndConnectionApplicationPacketsPhysicalLinkNetworkTransportApplicationExamplesTOC – Architecture – Internet Layers: Intro Examples 12345SignalsBitsPackets: End to EndConnectionApplicationPacketsPhysicalLinkNetworkTransportApplicationFiber-1Gbps; Cat5-100Mbps;Wireless; SONETEthernet; ADSL; …IP; ATM; …TCP; UDP; …DNS; HTTP; TFTP; RTPSpecificationsTOC – Architecture – Internet Layers: Intro Specification NN - 1N + 1• Interfaces: Formats, …• Functions: Service ProvidedTypically: State MachineEncapsulationTOC – Architecture – Internet Layers: Intro Encapsulation N + 1NN - 1HData Unit that N DeliversHeader: Control Info of NExamples of H:AddressesError Control CodesFraming DelimitersArchitecture EECS 1223FunctionsTOC – Architecture Internet Layers: Intro – Functions APPTRANNETLINKPHYModulation; DemodulationFraming; Error Coding;Local Addressing; SwitchingGlobal Addressing; Routing;ForwardingMultiplexing; Flow Control;Congestion ControlSet Up Connections; Presentation; …Layers Step By Step Physical Data Link Network Transport Application DNSTOC – Architecture – Layers Step By Step Physical In the beginning were two computers…TOC – Architecture – Layers Step By Step – Physical PhysicalModemRS232-CInterfaceInterface wiresModemRS232-CInterfaceInterface wiresSynchronous unreliable bit pipePhysical MediumPhysical Medium Virtual Bit Pipe1011011Example: Manchester EncodingTOC – Architecture – Layers Step By Step PhysicalData Link Control LayerData Link Protocol PhysicalInterfacePhysicalInterfaceSynchronous unreliable bit pipeData LinkControlData LinkControlAsynchronous reliable bit pipePhysical LinkFH DataBit Stream ! " # $ % & ' & # ( % ' # ( ) * +% , " )TOC – Architecture – Layers Step By Step – LinkData Link Control Layer What about a broadcast system?Example: Satellite, ethernet, 802.11Individual transmissions can interfere and destroy many framesA multiaccess protocol is required to try and avoid these collisions or the link will be too unreliableExample: TDM, CSMAMakes the bit-pipe provided by the physical layer look “intermittent” to the DLCProtocol must interface with Physical and DLC layersBy convention the Multiaccess Control Layer (MAC) is considered a “sub-layer” of the DLCTOC – Architecture – Layers Step By Step – LinkArchitecture EECS 1224Data Link Control Layer What about a broadcast system?PhysicalInterfacePhysicalInterfaceMultiaccessMediumPhysicalInterfaceMAC MACMACDLCDLCDLCNeed Addresses…Burned into NICsTOC – Architecture – Layers Step By Step LinkNetwork Layer: RoutingAB" - #./
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