CS 414 – Multimedia Systems Design Lecture 22 – Multimedia Extensions to Existing IP ProtocolsOutlineInternet Multimedia Protocol StackLayer 3 Internet ServicesNew Internet Protocol - IPngIP Packet HeadersQoS in Layer 3 - Internet Integrated ServicesIntegrated Services (IntServ) ArchitectureRSVPFlow Specification (1) (Traffic Shape General Parameters)Flow Specification (2) (in IntServ)Service Requirements (Application-specific)RSVP Control and Data FlowMixing ReservationsReservation StructuresRSVP FeaturesService ModelsGuaranteed Service (in IntServ)Guaranteed Service (2)Controlled Load Service (in IntServ)IntServ (Error Handling - Early Congestion Avoidance)IntServ (Error Handling) Discard AlgorithmsSlide 23Packet Scheduling (in IntServ)Packet Scheduling (in IntServ)IntServ/RSVP vs DiffServConclusionCS 414 - Spring 2011CS 414 – Multimedia Systems Design Lecture 22 – Multimedia Extensions to Existing IP Protocols Klara NahrstedtSpring 2011Outline Multimedia IP Extensions (Layer 3)CS 414 - Spring 2011Internet Multimedia Protocol StackCS 414 - Spring 2011AAL3/4 IP Version 4, IP Version 6 UDPMedia encaps(H.264, MPEG-4)RTPATM/Fiber OpticsEthernet/WiFiTCPSIPRTSP RSVP RTCPAAL5KERNELAPPLICATIONLayer 4(Transport)Layer 3(Network)Layer 2(Link/MAC)Layer 5(Session)MPLSDCCPLayer 3 Internet ServicesInternet Protocol (IP) – IP Version 4Provides unreliable deliver of datagrams in a point-to-point fashionRuns on top of any Layer 2 technologies Supports IP address of 32 bitsDifferent types of services (TOS)Precedence relationServices such as minimization of delay, maximization of throughput Multicast Internet Group Management Protocol for managing groupsCS 414 - Spring 2011New Internet Protocol - IPngNext Generation IP – IP Version 6Supports new featuresNew addressing and routingIP Address 128 bits Large hierarchical addresses, multicast addressesMore options of flow control and securityReal-time flowsEnd-to-end securityProvider selectionHost mobility Auto-configuration/auto-reconfigurationTraffic ClassesCS 414 - Spring 2011IP Packet HeadersCS 414 - Spring 2011Version Header Length TOS Total lengthidentification Flag Fragment offsetTime to Live (TTL) Protocol Header Checksum32 bit Destination IP Address32-bit Source IP AddressVersion Traffic Class Flow LabelPayload Length Next Header Hop limit128-bit Source IP Address128-bit Destination IP AddressIPv4IPv6QoS in Layer 3 - Internet Integrated ServicesTo provide network QoS in the Internet, IETF reacted by Creating Working Group (IntServ)Deploying Internet Integrated ServicesDevelopment of Control (Establishment) Protocol to reserve resources per flowResource Reservation Protocol (RSVP)Development of QoS-aware network services within IP Guaranteed class-of-service Deterministic QoS guaranteesControlled-load class-of-service Statistical QoS guaranteesCS 414 - Spring 2011Integrated Services (IntServ) ArchitectureCS 414 - Spring 2011Appl.RSVPdaemonPolicycontrolAdmissioncontrolPacketschedulerPacketclassificationRouting.RSVPdaemonPolicycontrolAdmissioncontrolPacketschedulerError HandlingReservation Protocol (RSVP)End-system RouterControl PlaneData PlaneRSVP Provides reservation for data flowsFlow specification is represented via Traffic specification, TSpec Characteristics of the data flowRequest specification, RspecDescription of required QoS (desired flow behavior)Is receiver-oriented and unidirectional Uses two types of messages:PATH messages and RSVP messagesProtocol 1. Send PATH message with TSpec from Sender to Receiver(s)2. Send RESV message with Rspec from Receiver(s) to Sender3. Send DATA with resulting reserved QoSCS 414 - Spring 2009Flow Specification (1)(Traffic Shape General Parameters) Peak rate – highest rate at which a source can generate trafficAverage rate – average transmission rate over a time intervalBurst size – max amount of data that can be injected into network at peak rateCS 414 - Spring 2009Flow Specification (2)(in IntServ) Traffic described in terms of token bucket parametersToken arrival rate ‘r’Bucket depth ‘b’Amount of bits transmitted during any interval of length t: A(t) ≤ r * t + bCS 414 - Spring 2009Service Requirements (Application-specific)Minimum Bandwidth - min. amount of BW required by applicationDelay – can be specified as average delay or worst case delayPropagation delay + Transmission delay + Queuing delayDelay Jitter – specifies max. difference between the largest and smallest delays that packets experienceLoss Rate – ratio of lost packets and total packets transmittedCS 414 - Spring 2009RSVP Control and Data FlowCS 414 - Spring 2009RESV messagesPATH messagesDATAS1D3D1D2R1 R2R3R4(1) TSpec(2) TSpec,RSpec(1) TSpec(1) TSpec(2) Tspec,RSpec(2) Tspec,RSpec(1)(1)(2)(2)(3)(3)(3)(3)(3)Mixing ReservationsCS 414 - Spring 2009RESV messagesPATH messagesDATAS1D3D1D2R1 R2R3R415MB10MB15MB15MB3MB12MBMixing3MB10MB15MB12MBMixing12MBReservation StructuresResource Reservation TableStores admitted/reserved resourcesRSVP MessagesCS 414 - Spring 2009Version FlagsSend TTLMessage TypeReservedRSVP ChecksumRSVP LengthRSVP FeaturesSimplex ReservationReservation only in one direction (simplex flow)Receiver OrientedSupports multicast communicationRouting IndependentPolicy IndependentSoft StateReservation state has timer associated with the stateWhen timer expires, state is automatically deletedRSVP periodically refreshes reservation state to maintain state along the pathCS 414 - Spring 2009Service Models Describe interface between network and its users in resource allocation architectureDescribe what services users can ask from network and what kind of resource commitments the network can offerIntServ standardGuaranteed ServiceControlled-load ServiceCS 414 - Spring 2009Guaranteed Service(in IntServ)Provides guaranteed BW and strict bounds on end-to-end queuing delay for conforming flowsControls max. queuing delayTSpec – describes traffic sourcesBucket rate (‘r’) (bytes/second)Peak rate (p) (bytes/second)Bucket depth (b) (bytes)Minimum policed unit (m) (bytes) – any packet with size smaller than m will be counted as m bytesMaximum packet size (M) (bytes) – max, packet size that can be acceptedCS 414 - Spring 2010Guaranteed Service
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