<p>Today, the Internet plays an vital part in our society. We rely greatly on the Internet to work, to communicate and to entertain. The Internet is a very large and complex computer network, consisting of tens of thousands of networks called autonomous systems (ASes). The key routing protocol for interdomain routing between ASes, Border Gateway Protocol (BGP), was invented three decades ago. Although BGP has undergone many improvements, many fundamental problems and limitations of BGP still exist today. For instance, BGP does not have the resiliency to attacks and good support for traffic engineering. To date, many evolutionary and revolutionary solutions have been proposed to address these problems. However, very few were adopted. While there are many reasons for this limited adoption, one may blame for the lack of deployability, scalability and more importantly adequate functionality.   SDN is a new networking paradigm that decouples the control plane and data plane. SDN breaks the ossification of the Internet and enables network innovations. SDN has been thoroughly investigated for the enterprise environment. This research investigates the application of SDN for interdomain routing in transit ASes. Specifically, the main goal is to study how SDN capabilities can be utilised to develop a scalable, programmable and flexible routing architecture for transit ISPs.</p>

<p>Today, the Internet plays an vital part in our society. We rely greatly on the Internet to work, to communicate and to entertain. The Internet is a very large and complex computer network, consisting of tens of thousands of networks called autonomous systems (ASes). The key routing protocol for interdomain routing between ASes, Border Gateway Protocol (BGP), was invented three decades ago. Although BGP has undergone many improvements, many fundamental problems and limitations of BGP still exist today. For instance, BGP does not have the resiliency to attacks and good support for traffic engineering. To date, many evolutionary and revolutionary solutions have been proposed to address these problems. However, very few were adopted. While there are many reasons for this limited adoption, one may blame for the lack of deployability, scalability and more importantly adequate functionality.   SDN is a new networking paradigm that decouples the control plane and data plane. SDN breaks the ossification of the Internet and enables network innovations. SDN has been thoroughly investigated for the enterprise environment. This research investigates the application of SDN for interdomain routing in transit ASes. Specifically, the main goal is to study how SDN capabilities can be utilised to develop a scalable, programmable and flexible routing architecture for transit ISPs.</p>