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Presenter: Robert Huang Advisor: Dr. Kai-Wei Ke 2015/5/20 A roadmap for traffic engineering in SDN-OpenFlow networks Slide 2 Outline The evolution of IT technology The evolution of Traffic engineering Overview of SDN architecture Overview of SDN traffic engineering The scope of Traffic engineering in SDN Flow management Fault tolerance Topology update SDN traffic analysis Conclusion 2 Slide 3 3 The Evolution of IT technology ( , ) Mainframe Ter. Server PC SD Clouding Driving technology Semiconductor Data communication Virtualization Web I/F Processing+Sensor (Smart device) Big data Machine learning Artificial Intelligence Slide 4 4 Characteristic of current network For Multi-media stream (Stable stream) Dedicated path/Circuit switch Admission control No retransmission For data stream (Burst stream) Shared path / OSPF routing algorithm) No admission control / with congestion control Retransmission mechanism to reach reliability target To reduced the business operation cost To build data convergence network Increasing performance & utilization vs Traffic engineering Slide 5 The evolution of Traffic engineering The purpose of Traffic engineering Lessons learned from the past TE for future data convergence network 5 Slide 6 6 The purpose of Traffic engineering Traffic engineering (TE) is an important mechanism to optimize the performance of a data network by dynamically analyzing, predicting, and regulating the behavior of the transmitted data. Slide 7 7 Lessons learned from the past ATM Network RTP SIP MPLS VPN CDN P2P IP-QoS Diffserv Intserv SNMP TCP/IP Core Network RoutingLoad- Balance Conges tion Distribut ed/Int. OSPF/B GP/IGP Static ECMP Implicit (Reno) Explicit (ECN) Slide 8 8 TE for future data convergence network Flow classification Routing / Load-balance / Utilization Hybrid (Central & Distributed) / Dynamic load detection Bandwidth enforcement Admission / Congestion Reliability (Restoration / Protection) Scalability (Central & Distributed) (Resource lim.) Traffic monitoring (Effectiveness) Slide 9 9 The mission of SDN ObjectCost Enhancing the Network layer function Decreasing the Application layer efforts for improving Network functions More complex core structure Separation of Data plane & Control plane More powerful control plane servers Simpler Data plane devices Slide 10 Overview of SDN architecture SDN architecture OpenFlow switch inside structure OF-Config protocol The OpenFlow protocol message types The critical issues in SDN OpenFlow multi-controller scheme OpenFlow multi-path scheme The major application scenario for SDN 10 Slide 11 11 Overview of SDN architecture Slide 12 12 The scenario of SDN Application SDN Applications Web I/F Slide 13 13 OpenFlow switch inside structure Pipeline Match Adder Group MeterQueue Flow Rate limit Drop Lower priority Min. rate queue Max. rate queue All Select Indirect Fast failover Action set Output Ports Counter (Flow / Port / Grp / Queue / Meter) Fail secure Fail standalone Slide 14 14 Open network foundation Slide 15 15 The OpenFlow protocol message types Controller-to-switch Features / Configuration / Modify-State / Read- State / Packet-out / Barrier / Role-request / Asynchronous-Configure Asynchronous Packet-in / Flow-Removed / Port-Status / Error Symmetric Hello / Echo / Experimenter Slide 16 16 A simple model of an OpenFlow switch Slide 17 17 The critical issues in SDN (Penalty) Reliability issue Controller single point failure Scalability issue New path setup latency Controller load The bandwidth between controller & switch Flow matching mechanism Match table size Matching speed WAN management Centralized vs distributed Slide 18 18 OpenFlow Multi-controller scheme Switch Controller (EQU) (Default) Controller (Master) (Only one) Controller (Slave) (Read only) Controller (Slave) Fast recovery from failure Controller load balance Clouding (Virtualization) Slide 19 19 OpenFlow Multi-path scheme Controller Switch Main (Datapath ID) AUX (AUX ID) Bandwidth improvement between controller & switch Slide 20 20 Slide 21 21 The major application scenario for SDN Highly dynamic user demanding and sensitive operation cost such as Clouding service provider Telecom. Operation service provider Slide 22 Overview of SDN Traffic engineering The scope of TE approaches in SDN Flow management Fault tolerance Topology update SDN traffic analysis 22 Slide 23 23 The scope of TE approaches in SDN Slide 24 24 SDN stack Slide 25 Flow management Switch load-balancing Hash-based ECMP flow forwarding Wildcard rule flow forwarding Controller load-balancing Logically distributed controller deployment Physically distributed controller deployment Hierarchical controller deployment Multi-thread controllers Generalized controllers Multiple flow tables 25 Slide 26 26 Slide 27 27 Slide 28 28 DevoFlow OpenFlow switch: Making local routing decision with matching microflows via wildcard OF rules OpenFlow controller: Maintaining the control over only targeted significant flows such as elephant flow or QoS significant flows Slide 29 29 DIFANE Slide 30 30 HyperFlow Slide 31 31 ONIX Slide 32 32 Kandoo Slide 33 Fault tolerance Fault tolerance for data plane Data plane restoration Data plane protection Fault tolerance for control plane Primary and backup controller coordination Backup controller deployment Distributed controller clusters in equal mode with a logical central view 33 Slide 34 Topology update Duplicate table entries in switches Per-packet consistency Per-flow consistency 34 Slide 35 SDN traffic analysis Monitoring framework Checking network invariants Debugging programming errors 35 Slide 36 Conclusion For availability & scalability issue Manage data flow efficiency at both the data plane and the control plane with the tradeoffs between latency and load- balance For consistency issue the SDN controller efficiently updates the network with consistency in real-time and safety without packet drops, and with low synchronization overhead 36 Slide 37 Conclusion For reliability issue In the data plane, fast failure recovery mechanisms should be implemented with low-overhead communications between the controller and the switches In the control plane, the fault tolerance mechanisms must consider a single point failure and should define an optimal number of controllers and the best location of controllers for the primary control and the backup controller(s) with a tradeoff between reliability and latencies of a variety of traffic patterns in the entire network 37 Slide 38 Reference 38 Ian F. Akyildiz, Ahyoung Lee, Pu Wang, Min Luo, Wu Chou, A roadmap for traffic engineering in SDN-OpenFlow networks Computer Networks 71 (2014) 1-30 Slide 39 Thanks for listening 39