Prof. Steve Uhlig and Dr.Hamed Haddadi from Queen Mary, University of London visited our lab on Feb 22, 2012. Prof. Steve Uhlig obtained his Ph.D. degree in Applied Sciences from the University of Louvain, Belgium, in 2004. His research interests include Internet measurements, software-defined networking, content delivery, network infrastructure virtualization. He serves as a TPC for many conferences include CoNext, IWQoS and IMC. Dr. Hamed is the lecturer in digital media at EECS School in Queen Mary, University of London. He is interested in understanding online social networks, advertising and privacy. He enjoys designing and building systems that enable better use of our digital footprint, while respecting users' privacy. He is also broadly interested in IP networks, animal social networks and complex systems. Prof.Uhlig gave a talk on Web content cartography, which is the identification and classification of content hosting and delivery infrastructures. In this talk he proposed a lightweight and fully automated approach to discover hosting infrastructures based only on DNS measurements and BGP routing table snapshots. He found that some popular content was served exclusively from specific regions and ASes. Furthermore, his classification enabled to derive content-centric AS rankings that complement existing AS rankings and shed light on recent observations about shifts in inter-domain traffic and the AS topology. Dr.Hamed gave a talk on the evolution of the AS topology from two different datasets over a period of years. He used a variety of metrics to analyse the structural disagreement revealed in the AS topologies inferred from two different datasets. The disagreement is due to the nature of the measurement techniques. He found that the traceroute dataset had increasing difficulty in sampling the periphery of the AS topology, while the BGP dataset did not sample the inner-most core of the network.