Research On The Optical Interconnections For Cloud Computing Data Center

Cloud computing can achieve greater IT efficiencies and agility by deploying service on a dynamic and shared IT infrastructure. It is attractive to the IT industry as it can not only reduce the up-front investment but also maintain an improved user experience. Data center is the core infrastructure for cloud computing. In cloud computing environment, network plays a more important role as large numbers of servers are operated in collaboration ways to solve the large scale data intensive applications. The evolutions of data center network are driven by new requirements including low transmission delay, high bisection bandwidth, good scalability and low power consumption. However, the traditional tree-based hierarchical network cannot meet these requirements. New electronic interconnections achieve high performance at the cost of high complicated topology, unsustainable power consumption and cable harness. With the development of the Photonic Integrated Circuit (PIC) and silicon photonic technology, optical interconnection attracts particular attentions. It can provide significant improvement over traditional electronic network because of high bandwidth, low power consumption and bit-rate transparency. Thus the optical interconnection is believed to be promising network architecture for cloud computing data center.Comparing with the centralized optical switching architecture, the distributed optical interconnection provides much higher scalability and agility. Hence in this dissertation, the key point of the research is to design the distributed optical network for data center. Since the nature traffic of data center is characterized by short mouse flows and large elephant flows, the combination of optical circuit switching and electrical packet switching can fully satisfy the requirements of mixed traffic flows. Two distributed hybrid architectures, Server-Centric Hybrid Mesh and Enhanced Hybrid Fat Tree, are proposed. To overcome the low bandwidth utilization of traditional optical circuit switching, the improved communication strategies and optical routers are designed in above architectures. Since all-optical interconnect architecture is considered as a long term solution that can sustain increasing bandwidth requirement with low power consumption, a distributed all-optical interconnection termed RingCube is proposed. It can achieve the flexible scalability and low node degrees by embedding hypercube in ring topology. To solve the drawbacks of the optical circuit switching, the traffic grooming scheme is proposed to enhance the efficiency of setting up an optical path. Furthermore, a rational wavelength allocation strategy is designed to support non-blocking all-to-all communications in the cluster and to achieve high connectivity between clusters.