Research Of Software Defined Networking And Integrated Control For DATA Center Optical Interconnection

With the rapid development of cloud computing services, as an important carrier providing the capacity of information storage and processing, data center is the core infrastructure to support the next generation of Internet technology. The rapid growth of internet users, the explosive increase of traffic demands, and changing service models cause the scale of the data center increases, the information flow among data centers grows, and the high-performance communication’s demand among massive information becomes more prominent. The traditional data center network where electrical switched is as the core technology meets the technical bottlenecks in terms of the bandwidth capacity, energy consumption and transmission distance. Optical interconnection becomes one of the key technologies to adapt the needs of large-scale data center networking with the advantages of large capacity, high bandwidth, and high efficiency, etc.Data center optical interconnection has the characteristics of resource and technology heterogeneity. Its networking and control face enormous challenges for the increasing number of users with a high level quality of service requirements. Specifically, data center optical interconnection has two main networking manners, one is from the resource form point of view, heterogeneous resources such as the access network, core network and data center are networked "heterogeneous-cross-stratum" along the horizontal direction; the other is from the traffic engineering point of view, the networks with various switching granularities are interconnected "multi-layer-carried" in the vertical direction. Then, three application scenarios are formed in the networking architecture, i.e., user access oriented interconnection between user and data center, inter-data center, and intra-data center optical interconnection scenarios. Around these different scenarios, there are a series of key networking and control problems in data center optical interconnection, such as the remote control for accessed user of data center service, multiple layers and stratums resources optimization in inter-data center, and time-aware resource scheduling in intra-data center.To solve these problems and challenges, this paper mainly researches on software defined networking and integrated control for data center optical interconnection. For networking of vertical "multi-layer-carried" and horizontal "heterogeneous-cross-stratum", the paper launches research work around application scenarios about the data center user access, inter-data center optical interconnection with photoelectric hybrid network, WDM optical network, and elastic optical network, and intra-data center. The model architecture, implementation mechanism and control strategy are analyzed and demonstrated on the experiment and simulation platform of data center optical interconnection. This paper will provide important references for future diverse applications of data center optical interconnection and software defined networking and control in practice. The main innovative research achievements are listed as follows.Firstly, for the features of flexible data center user access and high-level quality of service requirements, a novel data center application driven software defined access optical network (SDAON) architecture is proposed to solve the remote control problem in the data center user access application scenario, which can overcome the problems of rigid configuration and inefficient operation and maintenance in the traditional access network, implement remote unified control for OpenFlow-enabled passive optical network, and realize the dynamic resources scheduling and bandwidth on demand among different access optical network domains through designing protocols and control mechanisms and using service-aware flow scheduling strategy. OpenFlow-enabled SDAON experiment and simulation system is established to verify SDAON can enhance the resource utilization and QoS guarantee of each user effectively through unified control manner, and reduce the OPEX by remote interaction and operation.Secondly, for collaborative scheduling problem of multiple layers resources among electrical switched network, optical network and data center applications, a novel multi-stratum resources integration (MSRI) architecture is proposed based on multiple OpenFlow controllers cooperation in inter-data center scenario with supporting vertical "multi-layer-carried" photoelectric hybrid network, which designs service-aware flow estimation strategy and related protocol extensions and realization mechanisms, effectively overcomes the interworking limitations of multi-layer architecture, and determines which resource needs to be provisioned for the new flow through analyzing the previous flow statuses and estimating the network condition. Numeric results through experiment and simulation show that by exchanging resource information among multiple controllers, MSRI can effectively enable joint optimization of IP, optical networks and application resources, and enhance the data center responsiveness to end-to-end service demands. The achievement is invited to be published in the IEEE Journal of Optical Communications and Networking, and provides important references for practical multi-layer resource scheduling.Thirdly, around the high-performance network-based data center QoS requirements, cross stratum optimization (CSO) between network and application resources is researched in inter-data center scenario based on horizontal "heterogeneous-cross-stratum" WDM networking. A novel CSO-oriented unified control architecture in OpenFlow-enabled optical networks is proposed, which takes advantage of software defined network and provides unified abstraction about network and application resources, and realizes the CSO through dynamic global load balancing strategy and cross stratum resilience after a disaster. Experiment and simulation results show that CSO can enable a joint application and network resources optimization, responsiveness to quickly change demands from application to network, and enhance quality of application experience to realize Optical as a Service.Fourthly, for super-wavelength bandwidth and high-level end-to-end QoS requirements of data center services, a novel enhanced software defined networking (eSDN) architecture based on elastic optical network for data center application is proposed in inter-data center scenario based on horizontal "heterogeneous-cross-stratum" elastic optical networking, which can enable CSO of application and elastic optical network stratum resources, provide the elastic physical layer parameter adjustment based on the distance of path and network resource by using a transport-aware CSO strategy, and design multi-flow virtual concatenation (MFVC) and implementation model with using the noncontiguous spectrum fragments. The author completes the first eSDN experiment based on elastic optical network. The achievement is selected as a Post-deadline paper in OFC2013, which fills a gap for the domestic universities in the top optical communication conference.Fifthly, for the intra-data center service characteristics of high burstiness and time sensitivity, a novel time-aware software defined networking (TaSDN) architecture is proposed in OpenFlow-based intra-data center optical interconnection scenario to solve the problem of resource scheduling, and relevant protocols extension and realization mechanisms of TaSDN are designed. In the controller, a time-aware service scheduling strategy is introduced and deployed, which considers the data center service scheduling with flexible service time and service bandwidth according to the various time sensitivity requirements, by differentiating between delay-sensitive and delay tolerance services. Numeric results through experiment and simulation show that, TaSDN can arrange and accommodate the applications with required QoS considering the time factor, flexible network and application resources allocation, and enhance the data center responsiveness to quickly provide for intra-data center service demands.