Cost Optimization of Network Softwarization with Software Defined Networking and Network Function Virtualization

• Main Authors: Binayak Kar, 賓拿雅
• Other Authors: Eric Hsiao-Kuang
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/zzeh58

博士 === 國立中央大學 === 資訊工程學系在職專班 === 106 === Network softwarization is a paradigm shift based on cloud computing principles in the forms of SDN (Software Defined Networking), and NFV (Network Function Virtualization), in order to provide on-demand, cost-efficient and service-oriented networks on-the-fly. While SDN brings more flexibility in forwarding by its logically centralized architecture, NFV brings more flexibility in processing with its virtualization technology. This thesis presents three different approaches to address the cost issue of network softwarization using SDN and NFV. Our first approach is based on SDN and other two are based on NFV. Despite having smatter transmission scheduling in SDN network, SDN nodes may require to coexist with legacy nodes to form hybrid networks due to the large installed base of distributed legacy networks. Although, a hybrid network has better performance than a pure legacy network still rapid up-gradation to SDN is an issue due to the limited budget. To evaluate the relationship between cost and coverage in the hybrid network, we define the minimum percentage of SDN nodes in a path, and paths with at least one SDN node, as the hop coverage and path coverage, respectively. To evaluate the relationship between cost and coverage, we formulate SDN node selection as four optimization problems with hop/path coverage and cost as objectives and constraints, respectively, and vice-versa. We formulate SDN coverage problem both for the path and hop and propose two algorithms: 1) maximum number of uncovered path first (MUcPF) and 2) maximum number of minimum hop covered path first (MMHcPF). MATLAB experiment results demonstrate that our proposed algorithms have greater performance in terms of coverage, cost, and efficiency compared to other existing algorithms. NFV extends the virtualization to networking by virtualized network function (VNF) chaining to provide the required functionality at runtime on demand. These VNFs have a direct impact on power consumption of the physical machines (PM) on which they have placed. The PMs and varying load to these machines and their utilization are the critical issues of the energy consumption in the network. To address this energy issue, we designed a dynamic energy saving model with NFV technology and formulate an energy-cost optimization problem. We propose a Dynamic placement of VNF chains (DPVC) algorithm as a solution. The results show our algorithm performs better and saves more energy compared to other algorithms. Telecommunication carriers are re-architecting their central offices (CO) and mobile base stations as NFV data centers (DC), known as edge data center (EDC) that help network operators to speed deployment and reduce cost. Earlier the use of NFV was limited to within the DC. Recently there are numerous studies going on the use of NFV across DCs i.e., inter-DC. However, these NFV inter-DC architectures have limited the communication among DCs to either horizontal connectivity or vertical connectivity. We propose a generic architecture of these edge NFV data centers, with both horizontal and vertical connectivity and formulate a cost optimization problem to demonstrate the consequence of both vertical and horizontal connectivity between DCs in terms of communication and computing. We formulate a cost optimization problem with latency and capacity as constraints by estimating the traffic dispatch rate among DCs and propose a vertical-horizontal communication (VHC) heuristic solution. The obtained results show that the vertical connectivity helps to reduce the computing cost significantly compare to horizontal connectivity. However, both the vertical and horizontal communication together can help to reduce the communication cost and total cost compared to only vertical or horizontal communication.