DNS is a vital component for almost every networked application. Originally it was designed as an unencrypted protocol, making user security a concern. DNS-over-HTTPS (DoH) is the latest proposal to make name resolution more secure.

Assessing the impact of changes in a production network (e.g., new routing protocols or topologies) requires simulation or emulation tools capable of providing results as close as possible to those from a real-world experiment. Large traffic loads and complex control-data plane interactions constitute significant challenges to these tools. To meet these challengeswe propose a model for the fast and convenient evaluation of SDN as well as legacy networks. Our approach emulates the network's control plane and simulates the data plane, to achieve high fidelity necessary for control plane behavior, while being capable of handling large traffic loads. We design and implement a proof of concept from the proposed model. The initial results of the prototype, compared to a state-of-the-art solution, shows it can increase the speed of network experiments by nearly 95% in the largest tested network scenario.

Software-defined Internet eXchange points (SDXs) are a promising solution to the long-standing limitations and problems of interdomain routing. While the proposed SDX architectures have improved the scalability of the control plane, these solutions have ignored the underlying fabric upon which they should be deployed. In this paper, we present Umbrella, a software-defined interconnection fabric that complements and enhances those architectures. Umbrella is a switching fabric architecture and management approach that improves the overall robustness, limiting control plane dependence, and suitable for the topology of any existing Internet eXchange Point (IXP). We validate Umbrella through a real-world deployment on two production IXPs, TouSIX and NSPIXP-3, and demonstrate its use in practice, sharing our experience of the challenges faced.

It is well known that internet infrastructure deployment is progressing at a rapid pace in the African continent. A flurry of recent research has quantified this, highlighting the expansion of its underlying connectivity network. However, improving the infrastructure is not useful without appropriately provisioned services to exploit it. This article measures the availability and utilisation of web infrastructure in Africa. Whereas others have explored web infrastructure in developed regions, we shed light on practices in developing regions. To achieve this, we apply a comprehensive measurement methodology to collect data from a variety of sources. We first focus on Google to reveal that its content infrastructure in Africa is, indeed, expanding. That said, we find that much of its web content is still served from the US and Europe, despite being the most popular website in many African countries. We repeat the same analysis across a number of other regionally popular websites to find that even top African websites prefer to host their content abroad. To explore the reasons for this, we evaluate some of the major bottlenecks facing content delivery networks (CDNs) in Africa. Amongst other factors, we find a lack of peering between the networks hosting our probes, preventing the sharing of CDN servers, as well as poorly configured DNS resolvers. Finally, our mapping of middleboxes in the region reveals that there is a greater presence of transparent proxies in Africa than in Europe or the US. We conclude the work with a number of suggestions for alleviating the issues observed.

Innovation in interdomain routing has remained stagnant for over a decade. Recently, Internet eXchange Points (IXPs) have emerged as economically-advantageous interconnection points for reducing path latencies and exchanging ever increasing traffic volumes among, possibly, hundreds of networks. Given their far-reaching implications on interdomain routing, IXPs are the ideal place to foster network innovation and extend the benefits of software defined networking (SDN) to the interdomain level. In this paper, we present, evaluate, and demonstrate ENDEAVOUR, an SDN platform for IXPs. ENDEAVOUR can be deployed on a multi-hop IXP fabric, supports a large number of use cases, and is highly scalable, while avoiding broadcast storms. Our evaluation with real data from one of the largest IXPs, demonstrates the benefits and scalability of our solution: ENDEAVOUR requires around 70% fewer rules than alternative SDN solutions thanks to our rule partitioning mechanism. In addition, by providing an open source solution, we invite everyone from the community to experiment (and improve) our implementation as well as adapt it to new use cases.

The Software Defined Networking (SDN) paradigm can be successfully applied to the inter-domain ecosystem to empower network fabrics with finer grained policies and traffic engineering capabilities. However, introducing SDN at the inter-domain level might also lead to misconfigurations with potential to negatively impact on the Internet. Simulators are a popular approach to verify network behaviour and test applications before going into production. In the case of SDN, the available options do not scale for large scale networks nor high traffic loads. In this paper we propose a new simulator to foster SDN research and improve our understanding on the impact of the new use cases over the traffic flow. A simulation tool capable of efficiently reproducing large scale networks, high traffic loads, and policies, by abstracting the interactions between switches and controllers of the SDN network.