Research On Data Center Networks For Cloud Computing

Cloud computing has risen as a new computing model in a very short time. In order to provide IT resources in an efficient, flexible and pay-as-you-go way, cloud computing integrates such physical resources as computing and storage, and dynamically deploys business through the shared underlying physical structure. As the basic infrastructure of cloud computing, data center network determines the actual performance and real quality of the services and applications which cloud computing can provide. With the development of cloud computing services and applications, data center is facing more and more challenges. Traditional data center network has such problems as poor scalability, low network equipment utilization rate and high energy consumption. Several new data center architecture schemes have been proposed to solve the problems of the traditional data center network, but these schemes introduces some new problems such as high cost, cabling complexity and control difficulty. Compared with traditional electrical network, optical interconnection provides significant improvements in bandwidth, network latency performance, cost and energy consumption, and has won wide attention from researchers over the world.At first, we summarize the development of cloud computing and data center network and introduce the key technology used in cloud computing. We also introduce the impact and challenge brought by the development of cloud computing and list some typical data center network architectures. Then we analyze some optical devices and interconnection technologies that are most commonly used in data center network. Some newly proposed optical interconnection schemes for data center network are specially introduced and analyzed. Due to the large network scale and high construction cost of data center, we propose a cost-efficient hybrid architecture for data center network, which is called Cell-Tree. Cell-Tree combines the advantages of electrical switching and optical switching, and builds large scale network by adopting electrical switches and AWGRs to connect servers with dual network cards. We also design a shortest path routing algorithm for Cell-Tree according to its network structure. The simulation results show that Cell-Tree can achieve good network latency and throughput performance and can significantly reduce the equipment cost. Finally we propose an all optical interconnection data center architecture for future clouding computing environment, which is called OIT. OIT adopts low radix AWGRs to connect server racks to form cluster structures, then uses fibers to connect AWGRs in different clusters. These features enable OIT to have high bisection bandwidth and multipath characteristic. The simulation results show that OIT has good network latency and throughput performance. The analysis also proves that OIT supports different traffic patterns and has small equipment cost. This makes it a suitable topology candidate for data centers in the cloud computing era.