Review - EECS122TopicsHow Networks WorkLayersDNSTCPIPMPLS & DiffServMultiple AccessSwitchesPerformance ModelsPhysical LayerWirelessOptical NetworksSecurityCompressionExample: NetworkExample: ApplicationsSpeculations: FutureUCBReview - EECS122Jean WalrandU.C. Berkeleywww.eecs.berkeley.edu/~wlrUCBTopicsHow Networks Work: Internet, Ethernet, ATMLayers: IETF, IEEE, ATM, SONETDNSTCPIPMPLS/DiffServMultiple Access: TDMA, …, Ethernet, AlohaSwitchesPerformance ModelsPHY: Sonet, DSL, Modulation, …WirelessOptical NetworksSecurityCompressionUCBHow Networks WorkKey Ideas: Packets; IP/Link or LANApplications: HTTP, CDN, VoIPIP Addressing, packet by packet -> ScalableEnd-to-end principleEthernet: MAC address, ARP, …ATM: VC …Questions: Address translationsWhy is this scalable, extensibleDescribe packet formats, sequence of messagesUCBLayersIETF: APP/TCP, UDP/IP/MPLS/LINK, LAN/PHYIEEE: LLC/MAC/PHY for EthernetATM: AAL/ATMSONET: PATH/LINK/SECTION …Questions:Describe the layers of IP/ATM/SonetHow about IP/SonetUCBDNSStructure and ProtocolQuestions:How is this scalableReliabilityCachingSequence of messagesUCBTCPGo Back NNumbering of ACKsFlow Control: Receiver-Advertised WindowSlow Start – Congestion AvoidanceRTT and timeout estimationAdditive Increase – Multiplicative DecreaseJustification: Try to be fair and efficientImprovementsFast RetransmitFast RecoveryRED, RIOVegasUCBIPAddressingIP HeaderTTL, Fragmentation, DS fieldRouting: OSPF, RIP, BGP, MulticastRED, RIO, etcQuestions:Steps of OSPF, RIPWhy BGP?Why TTL, FragmentationWhy IPv6?Pros/Cons of single classUCBMPLS & DiffServObjectivesBasic MechanismsDRR etc; TCP/DRRDiffServ Admission ControlQuestions:Maximum rate for DiffServPaths for MPLSUCBMultiple AccessTDM, FDM, CDMAUnderstand pros and consAlohaThroughput, Delay CalculationsReservation AlohaThroughput, Delay CalculationsEthernetCSMA/CD OperationsQuestions:Calculate rates, delays, …UCBSwitchesInput, Output, VOB, Shared, ModularUnderstand OperationsPros and ConsSchedulingClassificationQuestions:Throughput comparisonsDelay comparisonsQoS PossibilitiesUCBPerformance ModelsBasic Queuing Model: M/M/1Poisson arrivals, Exponential lengthsP(X = n), E(X), E(T)Network of M/M/1 QueuesEach queue has same occupancy distribution as if it were M/M/1 with arrival rate given by flow conservation equationsE(Xk)E(T)UCBPhysical LayerDigital Link: bits -> [MOD] -> signals -> [DEM] -> bitsAdd error detectionDEM: Clock recovery + bit detectionModulation Schemes:Baseband: self-clocking or notBroadband: for wireless, for FDM, to exploit channel bandwidthExamples:Manchester, On/Off optical, QAM on copperSONET: Synchronize transmitters; protection with ringsDSL: Divide bandwidth into 4kHz channels; modulate channels based on SNRUCBWirelessThree Generations:Analog/Digital Circuits/PacketsCellular:Frequency reuse; HandoffWireless LAN:Multiple Access (Reservation)Ad-Hoc:Hop-by-hop with adaptive routingUCBOptical NetworksGenerations:Optical Links; O/E/O Circuits; O Circuits; O. Burst Switching; Devices: O. Amplifier; Wavelength Converters; Optical Switch; O. Memory; WDMConclusions: O Circuits in the core: Fast provisioning, protection switching; In core, routers can fill up a wavelengthIn MAN: WDM (O. Links)UCBSecurityComponents:Crypto (public and secret); HashingSystems:Confidentiality; Authentication; IntegrityUCBCompressionTypes:Lossless and LossyExamples:HuffmanLempel-ZivBlock CodesMotion PredictionUCBExample: NetworkEthernetATM/ADSLATMPoint-to-Point IP link(DHCP; framing)ATM VC(UBR)IP/ATM/SONETSONET PATHUCBExample: ApplicationsNetworkApplication Servers, Content Servers Caches, Storage, Traffic Shapers,Redirection Agents, ProcessingUCBSpeculations: FutureOptical Network in CoreWEB over WirelessNew services: Video Conferencing, Web Television, ?CDN, Storage(?), …New networks (?)Sensors Robust, IntegratedAfter
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