A QoS-based Resource Selection Approach for Virtual Networks

The Internet has gained an outstanding success in a short amount of time and it became a critical infrastructure for accessing information and global commerce. With the help of the Internet and its new channels for connecting people a new way of communication has been established. Meanwhile, its great success leads to new limitations. The Internet consists of various network infrastructure providers with different objectives which makes emerging of new technologies or major architectural changes that require cooperative agreements, relatively impractical. While the current Internet architecture is not suitable for supporting many types of applications, network virtualization is considered as promising, yet challenging solution of these limitations. Network virtualization separates the role of traditional internet service providers (ISPs) into physical infrastructure providers (PIPs) responsible for deploying the physical infrastructure and service providers (SPs) offering end-to-end services to end users. Another motivation for network virtualization is the possibility to add value in the virtualization layer aiming to make use of new technologies (e.g. QoS schemes) and customizing existing technologies to adapt specific services (i.e. customizable networks). This provides the means to run multiple virtual networks on a shared substrate network simultaneously while each virtual network is customized for a specific use. The key challenge in virtual networks is the problem of assigning virtual nodes and links to physical resources. Virtual network mapping/embedding consists in finding the most suitable physical nodes and links in the physical network in order to map virtual network requests with certain constraints on virtual nodes and links. The goal of this thesis is to design and implement substrate network resource selection scheme to increase the overall efficiency of the virtual network embedding process and satisfy the set of predefined resource constraints. This work assumes the existence of a virtual infrastructure provider requesting virtual networks from physical infrastructure providers and proposes a selection algorithm based on service-oriented architecture. Our proposed virtual network embedding algorithm is a heuristic algorithm that considers static attributes along with dynamic attributes of nodes and links as well as end-to-end QoS constraints.