Ignacio Castro

Inter-domain networking innovation on steroids: empowering ixps with SDN capabilities

While innovation in inter-domain routing has remained stagnant for over a decade, Internet exchange points (IXPs) are consolidating their role as economically advantageous interconnection points for reducing path latencies and exchanging ever increasing amounts of traffic. As such, IXPs appear as a natural place to foster network innovation and assess the benefits of SDN, a recent technological trend that has already boosted innovation within data center networks. In this article, we give a comprehensive overview of use cases for SDN at IXPs, which leverage the superior vantage point of an IXP to introduce advanced features like load balancing and DDoS mitigation. We discuss the benefits of SDN solutions by analyzing real-world data from one of the largest IXPs. We also leverage insights into IXP operations to shape benefits not only for members but also for operators.

Open Connect Everywhere: A Glimpse at the Internet Ecosystem through the Lens of the Netflix CDN

The importance of IXPs to interconnect different networks and exchange traffic locally has been well studied over the last few years. However, far less is known about the role IXPs play as a platform to enable large-scale content delivery and to reach a world-wide customer base. In this paper, we study the infrastructure deployment of a content hypergiant, Netflix, and show that the combined worldwide IXP substrate is the major corner stone of its Content Delivery Network. This highlights the additional role that IXPs play in the Internet ecosystem, not just in terms of interconnection, but also allowing players such as Netflix to deliver significant amounts of traffic.

Exploring HTTP Header Manipulation In-The-Wild

Headers are a critical part of HTTP, and it has been shown that they are increasingly subject to middlebox manipulation. Although this is well known, little is understood about the general regional and network trends that underpin these manipulations. In this paper, we collect data on thousands of networks to understand how they intercept HTTP headers in-the-wild. Our analysis reveals that 25% of measured ASes modify HTTP headers. Beyond this, we witness distinct trends among different regions and AS types; e.g., we observe high numbers of cache headers in poorly connected regions. Finally, we perform an in-depth analysis of the types of manipulations and how they differ across regions.

SDN-enabled Traffic Engineering and Advanced Blackholing at IXPs

While the clean slate approach proposed by Software Defined Networking (SDN) promises radical changes in the stagnant state of network management, SDN innovation has not gone beyond the intra-domain level. For the inter-domain ecosystem to benefit from the advantages of SDN, Internet Exchange Points (IXPs) are the ideal place: a central interconnection hub through which a large share of the Internet can be affected. In this demo, we showcase the ENDEAVOUR platform: a new software defined exchange approach readily deployable in commercial IXPs. We demonstrate here our implementations of traffic engineering and Distributed Denial of Service mitigation, as well as how member networks cash in on the advanced SDN-features of ENDEAVOUR, typically not available in legacy networks.

Umbrella: a deployable SDN-enabled IXP Switching Fabric

Software Defined internet eXchange Points (SDXs) are a promising solution to the long-standing limitations and problems of interdomain routing. While proposed SDX architectures have improved the scalability of the control plane, these solutions have ignored the underlying fabric upon which they should be deployed. This work makes the case for a new fabric architecture that proposes stronger control and data plane separation.

An SDN-inspired Model for Faster Network Experimentation

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 networks 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.

ENDEAVOUR: A Scalable SDN Architecture For Real-World IXPs

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.

Estimating the real with the virtual: How does the accuracy relate to the internet penetration?

Direct measurements of the real world are typically expensive and time-consuming. Recent studies have revealed the promising quick alternative where real-world characteristics are indirectly estimated based on data readily available in the Internet. Such methods for indirect virtual-world estimation of real-world properties rely on the implicit hypothesis that the estimation accuracy depends on how extensively the Internet penetrates into the real world. Our paper makes the first step towards validating this hypothesis. We adopt a simple statistical model to quantify the relationship between an index of consumer prices and online searches for respective categories of goods and services across 19 countries. We also show how the strength of this relationship depends on Internet-penetration and other socioeconomic variables.

Horse: towards an SDN traffic dynamics simulator for large scale networks

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.