Presentation on theme: "Autonomic QoS Management Mechanism in Software Defined Network"— Presentation transcript:
1 Autonomic QoS Management Mechanism in Software Defined Network Speaker: Chang, Cheng-YuAdvisor : Dr. Kai-Wei KeDate: 09/Dec./2014
2 Outline Introduction Quality of Service Software Defined Network Autonomic QoS Management Mechanism in SDN (AQSDN)Packet Context-aware QoS model (PCaQoS)Experimental EvaluationConclusionReferences
3 IntroductionAs the increment of various network equipments and services, the complexity of network control and management has risen sharply in recent years.The QoS management is an important part of network management.Various QoS models and mechanisms have been proposed, but there is no one-fit-all algorithm.The self-configurable QoS models and mechanism based on the context- aware are highly expected.
4 Introduction (Cont.)In order to reduce the network management cost and the probability of network failure.Both Software Defined Network(SDN) and Autonomic Network technologies are sophisticated technologies for the network control and management.Design an Autonomic QoS management mechanism in SDN for network QoS guarantee.In this mechanism, the controller undertakes the function of analysis and decision in the autonomic control loop.
5 Quality of ServiceThe goal of QoS is to provide guarantees on the ability of a network to deliver predictable results.Elements of network performance within the scope of QoS often includeavailability (uptime)bandwidth (throughput)latency (delay)error rate
6 Quality of Service (Cont.) Mark and Classify packets according to policies and the behavior of the traffic. This is carried out with technologies such as IP Precedence and DSCP and is most effective.Congestion management by prioritising traffic based on the marks using queuing technologies that can respond to traffic classes.Avoid congestion by dropping packets that are not a high priority using technologies such as Random Early Detection.Limit the ingress or egress traffic depending on the class/markings of the packets. Also perform traffic shaping to maximise the use of bandwidth by specifying peak and average traffic rates.Fragment and compress packets to maximise the use of WAN bandwidths.
7 Quality of Service (Cont.) Important QoS technologies / protocols:Class of Service [802.1p/Q] - layer 2Integrated Services (IntServ) - layer 3Differentiated Services (Diffserv) - layer 3
8 Class of Service [802.1p/Q]Layer 2 Class of Service can be provided within the TCI field of the Ethernet framePriorityServices0 (最低)Routine12Immediate3Flash4Flash Override5Critical6Internetwork Control7 (最高)Network Control
9 Integrated Services (IntServ) Manages traffic on a per-flow basisProvides customized services per traffic streamEnd-to-end application registrationResource Reservation Protocol (RSVP)
10 Differentiated Services (Diffserv) Manages traffic on a type-of-traffic basisDoes not provide individual stream visibilityImplemented per hopType of Service(ToS), DiffServ Code Point (DSCP)
12 AQSDN ArchitectureThe QoS control module decides or chooses QoS rules dynamically.
13 QoS control moduleIs an application of the controller, has two function models:QoS scheme decision model: determines suitable queue management and scheduling scheme as well as their parameters. (infrequently)QoS action decision model: determines packets marking and designates the queue for each adaptively. (frequently)QoS schemes and actions collectively referred as QoS rules.
14 QoS control module: DB Requirement DB: stores the QoS requirements Rule DB: stores the historical QoS rulesPolicy DB: stores the QoS Polices supported by OpenFlow switch
15 QoS control module: Context manager In QoS management include network context and flow contextNetwork Context:State information (e.g., utilization ratio of CPU, length of Packet queue)Link information (e.g, Packet loss ratio delay, jitter, bandwidth of link)Flow Context:Inherent feature (e.g., service type, QoS requirement)Real-time flow featue (e.g., burst rate)
16 QoS control module: Analysis Analyze whether the QoS requests can be satisfied and if there are conflicts among them.If conflicts are founded or the QoS request could not be satisfied:-> Sent to the administratorIf the QoS requests could be satisfied:-> Forwarded contexts and requirements to the QoS rule decision module
17 QoS control module: Rule decision Can chooses the appropriate QoS rule from the QoS Rule DB.If Rule DB not exits: Plans new QoS rule(include context, requirement, policy) and stores into the Rule DB.
18 QoS actionThe packet marking algorithms selection is configured via OpenFlow protocol by OpenFlow controller.The meter table and meter band which is defines by OpenFlow protocol provide the meter operation for flow.The existing remarking bands remarking bands, which only lower the drop precedence level of the packet, does not satisfy various QoS requirement.It is necessary to extend OpenFlow protocol so that it could support diverse packet marking algorithms.
19 QoS action (Cont.)We explore the specific arguments instead of the predefinition of the structure for each meter band.We add two packet marking algorithms as new meter bands, Single Rate Three Color Marker(srTCM) and Packet Context-aware Packet Marker(PCaPM)OpenFlow 1.3.1: Switch Hardware (Forwarding Plane)
20 QoS schemeFor each queue, queue management, schedule schemes are configured through OF-Config protocol.The existing OF-Config has provided the support of the minimum and maximum transmission rates of a queue.For supporting the configuration of Queue management and Queue scheduling schemes, we enrich the operate set of the OF-Config on the content layer.
21 QoS scheme (Cont.) PQ: Priority Queue WRR: Weighted Round-Robin WRED: Weighted Random Early Detection
22 Packet Context-aware QoS Model (PCaQoS) Process packets according to their semantic precedence level.The QoS guarantee ability would be improved if the SDN take packet context into account.It is impractical to deliver the packet context to the controller because this needs the frequent communication between the switch and the controller.Design the PCaQoS enhanced from the DiffServ model, which enables the switch to perceive the packet context and responds it locally.
23 PCaQoS (Cont.)In addition to the metering information about the flows, the marker and the queue manager also take the packet contexts into account.They called as Packet Context-aware Packet Marker (PCaPM) and Packet Context-aware Queue Management (PCaQM)logical view of packet classification and traffic
24 Packet Context-aware Packet Marker (PCaPM) PCaPM initiate a multicolor packet marker by remarking the DSCP code based on the packet context and the marking result of the metering-based marker.The metering-based marker is srTCM, the packets of a service present three kinds of priority (high, middle and low) and the mapping relationships from meter result to remarking color.Single Rate Three Color Marker(srTCM) marks packets as either Green, Yellow, or Red. [RFC 2698]
26 Packet Context-aware Queue Management In a congested route, if lots of lower priority packets arrive suddenly in a short time, the queue length increases sharply so that the heiger priority packets coming later will be dropped.So PCaQM takes packet priority as another metric for the icoming packets processing.
27 PCaQM (Cont.)PCaQM derives k virtual sub queues from the original queue. (k is colors or priorites)All of packets with the same priority l(1≤l≤k) in original queue Q compose sub queue sq[l].
29 Experimental Evaluation The prototype system of AQSDN, which config QoS polices in SDN according to the policy of multimedia service autonomically.Controller: Dell R710 run NOX platformSwitches: run Ofsoftswitch13 support both DiffServ and PCaQoSBandwidth between CS1 and CS2 is 20Mbit/sBandwidth of any other link is 100Mbit/sPCs serve as source and destination hosts.The implementation of prototype system
30 The self-configuration feature of the AQSDN In order to compare PCaQoS and DiffServ, we drive two virtual network.First virtual networkSecond virtual networkSwitchesES1, CS1, CS2ES2, CS1, CS2, ES4Flow classificationandQueue schedulingVedio flows: AF class (PQ+WRR)Background flows: AF and BF(WRR) classPacket markerAndQueue managementES1: srTCMOther: WREDES2: PCaPMOther: PCaQMReferred to asDiffServ based networkPCaQoS based network
31 PCaQoS vs. DiffServPresent the average Peek Signal to Noise Ratio(PSNR) of each video after across PCaQoS and DiffServ based network respectively.
32 PCaQoS vs. DiffServ (Cont.) Select 300 continuous frames from three videos after across the PCaQoS and DiffServ based network respectively, and analyze their PSNR.
33 ConclusionIn the traditional IP network, resource utilization improvement and network QoS guaranteeing are very complicated for network operators.Propose them is to upgrade the network nodes with autonomic abilities.SDN provides the capability to implement network control and management functions by software
34 Conclusion (Cont.)The AQSDN architecture, which combines the advantages of the autonomic network management and the SDN technologies.A novel QoS model which is called PCaQoS model is also presented based on the AQSDN architecture.The self-configuration feature of the AQSDN and the enhancement of video quality of the PCaQoS model are verified.
35 ReferenceWang Wendong. “Autonomic QoS Management Mechanism in Software Defined Network.” China Communications, vol.11, pp July 2014.