Sampling a large network with a given distribution has been identified as a useful operation to build network overlays. For example, constructing small world network topologies can be done by sampling with a probability that depends on the distance to a given node. In this talk we describe algorithms that can be used by a source node to randomly select a node in a network with probability distributions that depend on their distance.

Vehicular ad hoc networks have proven to be quite useful for broadcast alike communications between nearby cars, but can also be used to provide Internet connectivity from vehicles. In order to do so, vehicle-to-Internet routing and IP address autoconfiguration are two critical pieces. TREBOL is a tree-based and configurable protocol which benefits from the inherent tree-shaped nature of vehicle to Internet traffic to reduce the signaling overhead while dealing efficiently with the vehicular dynamics.

BitTorrent is one of the most popular application in the current Internet. However, we still have little knowledge about the topology of real BitTorrent swarms and how the traffic is actually exchanged among peers. This paper addresses fundamental questions regarding the topology of live BitTorrent swarms. For this purpose we have collected the evolution of the graph topology of 250 real torrents from its birth during a period of 15 days. Using this dataset we first demonstrate that real BitTorrent swarms are neither random graphs nor small world networks.

Access networks include modems, home gateways, and DSL Access Multiplexers (DSLAMs), and are responsible for 70-80% of total network-based energyconsumption. In this paper I'll take an in-depth look at the problem of greeningaccess networks, identify three root problems, and propose practical solutionsfor their user- and ISP-parts. On the user side, the combination of  continuous light traffic and lack of alternative paths condemnsgateways to being powered most of the time despite having Sleep-on-Idle (SoI) capabilities.

Fake content represents an important portion of those files shared in BitTorrent. In this paper we conduct a large scale measurement study in order to analyse the fake content publishing phenomenon in the BitTorrent Ecosystem. Our results reveal that a few tens of users are responsible for 90% of the fake content. Furthermore, more than 99% of the analysed fake files are linked to either malware or scam websites. This creates a serious thread for the BitTorrent ecosystem.

Sleep modes are emerging as a promising technique for energy-efficient networking: by adequately putting to sleep and waking up network resources according to traffic demands, a proportionality between energy consumption and network utilization can be approached, with important reductions in energy consumption. Previous studies have investigated and evaluated sleep modes for wireless access networks, computing variable percentages of energy savings.

Twitter is one of the most used applications in the current Internet with more than 200M accounts created so far. As other large-scale systems Twitter can obtain benefit by exploiting the Locality effect existing among its users. In this paper we perform the first comprehensive study of the Locality effect of Twitter. For this purpose we have collected the geographical location of around 1M Twitter users and 16M of their followers. Our results demonstrate that language and cultural characteristics determine the level of Locality expected for different countries.

In this brief announcement we propose B-Neck, a max-min fair distributed algorithm that is also quiescent. As far as we know, B-Neck is the first max-min fair distributed algorithm that does not require a continuous injection of control traffic to compute the rates. When changes occur, affected sessions are asynchronously informed, so they can start the process of computing their new rate (i.e., sessions do not need to poll the network for changes). The correctness of B-Neck is formally proved, and extensive simulations are conducted. In them it is shown that B-Neck converges relatively fast and behaves nicely in presence of sessions arriving and de- parting.

The technological advancement and information overload in recent years increased the popularity of Distributed Storage Systems where the data is replicated and maintained at multiple disks or servers residing at different network locations. While replication is sufficient to ensure data survivability, it raises an important question: "How can we efficiently maintain consistency among the replicas, despite system asynchrony and failures?"
 

As wireless ad hoc networking becomes more and more popular and ad hoc networks are used for an increasing number of applications, the integration of these networks in today's Internet, still mostly organized as a set of interconnected fixed and wired networks, becomes a key research field in the computer networking domain.