Analyzing the potential benefits of CDN augmentation strategies for internet video workloads

Video viewership over the Internet is rising rapidly, and market pre-dictions suggest that video will comprise over 90 % of Internet traf-fic in the next few years. At the same time, there have been signs that the Content Delivery Network (CDN) infrastructure is being stressed by ever-increasing amounts of video traffic. To meet these growing demands, the CDN infrastructure must be designed, pro-visioned and managed appropriately. Federated telco-CDNs and hybrid P2P-CDNs are two content delivery infrastructure designs that have gained significant industry attention recently. We ob-served several user access patterns that have important implica-tions to these two designs in our unique dataset consisting of 30 million video sessions spanning around two months of video view-ership from two large Internet video providers. These include par-tial interest in content, regional interests, temporal shift in peak load and patterns in evolution of interest. We analyze the impact of our findings on these two designs by performing a large scale measurement study. Surprisingly, we find significant amount of synchronous viewing behavior for Video On Demand (VOD) con-tent, which makes hybrid P2P-CDN approach feasible for VOD and suggest new strategies for CDNs to reduce their infrastructure costs. We also find that federation can significantly reduce telco-CDN provisioning costs by as much as 95%

Demand based State Aware Channel Reconfiguration Algorithm for Multi-Channel Multi-Radio Wireless Mesh Networks

Efficient utilization of Multi Channel - Multi Radio (MC-MR) Wireless Mesh Networks (WMNs) can be achieved only by intelligent Channel Assignment (CA) and Link Scheduling (LS). Due to the dynamic nature of traffic demand in WMNs, the CA has to be reconfigured whenever traffic demand changes, in order to achieve maximum throughput in the network. The reconfiguration of CA requires channel switching which leads to disruption of ongoing traffic in the network. The existing CA algorithms for MC-MR WMNs in the literature do not consider the channel reconfiguration overhead that occurs due to this channel switching. In this paper, we propose a novel reconfiguration framework that considers both network throughput and reconfiguration overhead to quantitatively evaluate a reconfiguration algorithm. Based on the reconfiguration framework, we propose an online heuristic algorithm for CA called Demand based State Aware channel Reconfiguration Algorithm (DeSARA) that finds the CA for the current traffic demand by considering the existing CA of the network to minimize the reconfiguration overhead. We show through simulations that DeSARA outperforms both static CA and fully dynamic CA in terms of total achieved throughput

InfoNames: An Information-Based Naming Scheme for Multimedia Content

Recent proposals have argued for data-centric mechanisms that decouple data delivery from the sources of the data and the transfer protocols. We take this idea to its logical completion and argue for enabling content distribution schemes to name and query directly for the underlying 'information'. The motivation for this information-aware design is that we see a proliferation of diverse producers of multimedia content offering varying presentation modes and significant heterogeneity in the operating conditions of Internet-enabled devices that seek access to such multimedia content. In addition to decoupling content from available sources and transfer protocols, information-aware names, or InfoNames, explicitly decouple the information from content presentation. Thus, it enhances availability and allows users to maximally leverage sources of multimedia content offering diverse presentation formats. Further, users and providers benefit from having additional flexibility to dynamically adapt content delivery depending on application and network constraints. In this report, we address the first challenge to realizing this idea - How should we 'name information' in multimedia content in a way that is invariant across presentation formats and can be consistently generated/verified without relying on a centralized authority? We leverage techniques from the multimedia and computer vision communities, and propose a set of algorithms for naming, and comparing InfoNames. An extensive evaluation of the proposed schemes on a controlled dataset of images and videos is presented. In addition, an 'in-the-wild' study with a set of videos download from Youtube is also described