Research On Architecture And Embedding Algorithm Of Resource Management For Network Virtualization

The Internet has profoundly affected the way people live and work. It makes a great contribution on economic development and social progress. However, the architecture of Internet faces a range of issues and difficulties such as scalability, security, mobility, quality of service and energy consumption after 40 years of development. It is more difficult to adapt to the rapid expansion of the global network scale and meet the needs of new applications and traffic.Network virtualization technology plays an important role in solving the ossification problem of Internet. It supports diverse virtual networks sharing the common substrate network by abstraction and isolation mechanism essentially. Network virtualization allocates and schedules resource optimally to maximize the resource utilization and decrease the operation and maintenance cost. The above flexibility and advantage of network virtualization brings great challenge to the virtual resource management.This dissertation focuses on the scalable and autonomous resource management architecture, the efficient node mapping optimization algorithm based on node stress and the effective link mapping optimization algorithm based on link stress. The major works are outlined as follows:1. The resource management architecture of network virtualization has the issue of worse scalability and autonomy. To address these issues, we design a resource management architecture based on multi-domain and hierarchy. It adapts to the substrate network composed of multiple infrastructure provider domains. The architecture is composed of a Global Scheduler and several Local Schedulers. The Global Scheduler is responsible for the access control, virtual network partition and global embedding scheduling. And the Local Schedulers complete the sub-virtual network embedding in parallel and deal with the local virtual resource discovery, failure and mobility management independently. The hierarchical architecture reduces the management complexity, improves the efficiency and satisfies the real-time requirement of virtual network embedding. Additionally, it takes advantages of both the central and distributed resource management architectures. It can not only solve the single point failure and performance bottleneck problems caused by centralized models but also reflect the dynamic and autonomous characteristics of resource very well.2. Existing virtual network embedding algorithms are usually decomposed into two steps:virtual node mapping and virtual link mapping. This decomposition helps reduce the overall complexity of resource allocation for virtual network requests since the virtual network embedding problem is NP-hard. Embedding the virtual node efficiently can promote the performance of the whole virtual network embedding algorithm greatly. We propose two different node mapping algorithm based on node stress to promote the performance of virtual network embedding. First, a node mapping algorithm based on minimum node stress priority is proposed to improve the load balancing of substrate node. It sorts of node stress in order to allocate the node resource balanced. Simulation experiments show that the proposed algorithm achieves the same embedding efficiency and improves the load distribution of substrate nodes distinctly while reducing the average substrate node stress significantly. Another novel node mapping algorithm is proposed based on the maximum node stress priority when the scale of virtual network is equal to that of substrate network. It aims to maximize the substrate node utilization in the node mapping stage to improve the efficiency of virtual network embedding. Simulation experiments show that the proposed algorithm improves the revenue and acceptance ratio of virtual network embedding significantly.3. A load-aware virtual network mapping algorithm is proposed based on the status feedback of link stress. It deals with the online virtual network requests with priority scheduling defined by mapping revenue. The main contribution is to embed the virtual network requests according to the current load distribution of substrate network. This adaptive algorithm differentiates the residual bandwidth of substrate links and takes full advantage of the multi-path to improve the load balancing of the substrate network by the status feedback factor. Simulation experiments show that the proposed algorithm achieves the same embedding efficiency and improves the load distribution of substrate network distinctly while reducing the average substrate link stress significantly. Finally, we combine the node mapping algorithm based on minimum node stress priority and the link mapping algorithm based on status feedback of link stress to do simulation. The results show that the combined algorithm can reduce the maximum node stress and maximum link stress simultaneously and improve the node load balancing and link load balancing significantly.