We study the detection of the provider-free AS set (PFS), i.e., the set of those Autonomous Systems (ASes) that reach the entire Internet without paying anyone for the traffic delivery. Using trustworthy but non-verifiable sources for sanity checks, we derive the PFS from public datasets of inter-AS economic relationships. Whereas a straightforward method for extracting the PFS performs poorly because the datasets are noisy, we develop a more sophisticated Temporal Cone (TC) algorithm that relies on topological statistics and exploits the temporal diversity of the datasets. The evaluation shows that our TC algorithm detects the PFS with a high accuracy.

In the era when Facebook and Twitter dominate the market for social media, Google has introduced Google+ (G+) and reported a significant growth in its size while others called it a ghost town. This begs the question that "whether G+ can really attract a significant number of connected and active users despite the dominance of Facebook and Twitter?".

It is common practice for network operators, usually for traffic engineering purposes, to propagate more specific prefixes (overlapping prefixes) along with shorter prefixes that cover them. On the other hand, it can be beneficial for some Autonomous Systems (ASes) to filter such overlapping prefixes

Ponente: Iljitsch van Beijnum, Ayudante de Investigación, Institute IMDEA Networks
Lugar: Aula 4. 1F03, Departamento de Telemática, Edificio Torres Quevedo, Universidad Carlos III de Madrid, Avda. Universidad, 30, 28911 Leganes – Madrid
Fecha: 25 de mayo 2011, 13:00
Organización: NETCOM Research Group (Departamento de Telemática, Universidad Carlos III de Madrid, España); Institute IMDEA Networks (Madrid, España)
 

El seminario se impartirá en inglés

At Spotify we try to connect millions of people with their favorite music and build the best music service in the world. We believe that music should be easily accessible and than listening to music improves everybody lives. But achieving this goal is not easy and our team needs to face all kind of problems: from scalability issues to coordinate 200 engineers working together. One of our backend engineers will talk about how Spotify solves these issues from the moment you press Play.

Objectives of the meeting: Review status of the internal specifications milestones, synchronization intra and inter work packages and coordination for future work.

La importancia de las redes inalámbricas para la Futura Internet crece a un ritmo acelerado a medida que los dispositivos móviles se convierten cada vez más en su punto de acceso. No obstante, y como consecuencia de su diseño arquitectónico rígido, las redes inalámbricas actuales no son capaces de adaptarse rápidamente a contextos y necesidades de servicio evolutivos. Creemos que la capacidad de Internet para mantenerse al día con la innovación procede directamente de su dependencia de la abstracción tradicional de una Internet basada en capas.

ISPs (Internet Service Providers) typically operate as commercial ASes (Autonomous Systems) and obtain revenue by delivering IP (Internet Protocol) traffic of their customers. In particular, the provider-free ASes - which reach the entire Internet without paying anyone for the traffic delivery - sell IP transit to numerous other ASes. IP prefix deaggregation gives the deaggregator some control over Internet traffic flows but increases the memory requirements of IP routers.

Game theoretical techniques have recently become prevalent in a wide range of engineering applications, notably, in wireless and communication networks. With the emergence of novel networking paradigms such as cognitive radio or cooperative communications and the need for self-organizing and decentralized networks, it has become imperative to seek game theoretical tools that allow studying and analyzing the interactions of the nodes in future communication networks. In this talk, following a brief overview on the fundamentals and potential of game theory, we put a particular emphasis on coalitional game theory, which is a branch of game theory that deals with cooperative behavior.

We are entering an era where accurately synchronized clocks are economical and are becoming commonplace. Commercial GPS units synchronize clocks within 10’s of micro-­‐seconds. Chip sets that implement the IEEE 1588 standard are synchronizing clocks within a fraction of a nano-­‐second to improve the probability of collisions in particle colliders.