Optimal content delivery with network coding

We present a unified linear program formulation for optimal content delivery in content delivery networks (CDNs), taking into account various costs and constraints associated with content dissemination from the origin server to storage nodes, data storage, and the eventual fetching of content from storage nodes by end users. Our formulation can be used to achieve a variety of performance goals and system behavior, including the bounding of fetch delay, load balancing, and robustness against node and arc failures. Simulation results suggest that our formulation performs significantly better than the traditional minimum k-median formulation for the delivery of multiple content, even under modest circumstances (small network, few objects, low storage budget, low dissemination costs)

Dynamic Server Selection by Using a Client Side Composite DNS-Metric

Dynamic Server Selection (DSS) is a new DNS method for the optimal server selection of a multiple available network service. The method allows dynamic selection of a server on the client side based on the information of the server load and its network topological distance from the client. The server selection is based on the calculations of a composite DNS-metric in which servers, whose IP addresses are sent in a DNS response, are ranked from the optimal to the least suitable. Calculation parameters are server response time, which the client measures for each server independently, and the server load, which is specified by the server administrator. The DSS method has the lowest overall network service response time in comparison with the other four observed methods (Geographical, Hops, Random and RTT) which, in measurements done in a real time environment, have longer response time from 8.5% to 26.8% compared to DSS

Distributed Information Object Resolution

The established host-centric networking paradigm is chal-lenged due to handicaps related with disconnected opera-tion, mobility, and broken locator/identifier semantics. This paper soberly examines another topic of great interest: distributed information object resolution. After recapping the notion of an information object, we review object resolution in today’s Internet which is based on Uniform Resource Identifiers (URIs). We revisit the implications of DNS involvement in URI resolution and discuss how two different types of content distribution networks work with respect to name resolution. Then we evaluate proposals championing the replacement of DNS with alternatives based on distributed hash tables. We present the pros and cons and highlight the importance of latency in resolution. The paper positions these issues in the context of a Network of Information (NetInf) and concludes with open research topics in the area. 1

The Impact of Time on DNS Security

Time is an important component of the Domain Name System (DNS) and the DNS Security Extensions (DNSSEC). DNS caches rely on an absolute notion of time (eg August 8, 2018 at 11:59pm\u27\u27) to determine how long DNS records can be cached (i.e their Time To Live (TTL)) and to determine the validity interval of DNSSEC signatures. This is especially interesting for two reasons. First, absolute time is set from external sources, and is thus vulnerable to a variety of network attacks that maliciously alter time. Meanwhile, relative time (e.g. 2 hours from the time the DNS query was sent\u27\u27) can be set using sources internal to the operating system, and is thus not vulnerable to network attacks. Second, the DNS on-the-wire protocol only uses relative time; relative time is then translated into absolute time as a part of DNS caching, which introduces vulnerabilities. We leverage these two observations to show how to pivot from network attacks on absolute time to attacks on DNS caching. Specifically, we present and discuss the implications of attacks that (1) expire the cache earlier than intended and (2) make the cached responses stick in the cache longer than intended. We use network measurements to identify a significant attack surface for these DNS cache attacks, focusing specifically on pivots from Network Time Protocol (NTP) attacks by both on-path and off-path attackers. We therefore recommend that DNS resolvers stop using absolute time for caching, and instead start using relative time. We have implemented our recommendations as part of the popular Unbound open source resolver, and our implementation will be part of Unbound\u27s upcoming release

SCOPE: Synergistic Content Distribution and Peer-to-Peer Networks

Distributing content on the Internet is an important economic, educational, social, and cultural endeavor. To this end, several existing efforts use traditional server-based content distribution networks (CDNs) to replicate and distribute Web and multimedia content of big content producers, such as news Web sites, or big businesses, such as online shopping websites, etc., to millions of Internet users. This approach places a large number of content servers at strategic locations on the Internet, incurring a very large deployment and operating cost. Therefore, it is available only to some wealthy companies/organizations. Individual users and small content publishers may rely on a more economical content dissemination approach based on recent peer-to-peer technology to distribute their own content. Nevertheless, it is the ephemeral and the limited resources nature of peer-to-peer networks that hinder a wide spread adoption of peer-to-peer technology as a reliable content distribution solution. It is, therefore, important that a new generation of cost-effective and reliable content distribution framework be proposed and investigated. Building on the successes and failures of previous content distribution approaches, the proposed research goal is to find and evaluate a Synergistic Content Distribution and Peer-to-Peer Networks (SCOPE). SCOPE leverages the reliability and the resourcefulness of traditional server-based CDNs while tapping on the economical and dynamic resources of peers

A NOVEL LINEAR DIOPHANTINE EQUATION-BAESD LOW DIAMETER STRUCTURED PEER-TO-PEER NETWORK

This research focuses on introducing a novel concept to design a scalable, hierarchical interest-based overlay Peer-to-Peer (P2P) system. We have used Linear Diophantine Equation (LDE) as the mathematical base to realize the architecture. Note that all existing structured approaches use Distributed Hash Tables (DHT) and Secure Hash Algorithm (SHA) to realize their architectures. Use of LDE in designing P2P architecture is a completely new idea; it does not exist in the literature to the best of our knowledge. We have shown how the proposed LDE-based architecture outperforms some of the most well established existing architecture. We have proposed multiple effective data query algorithms considering different circumstances, and their time complexities are bounded by (2+ r/2) only; r is the number of distinct resources. Our alternative lookup scheme needs only constant number of overlay hops and constant number of message exchanges that can outperform DHT-based P2P systems. Moreover, in our architecture, peers are able to possess multiple distinct resources. A convincing solution to handle the problem of churn has been offered. We have shown that our presented approach performs lookup queries efficiently and consistently even in presence of churn. In addition, we have shown that our design is resilient to fault tolerance in the event of peers crashing and leaving. Furthermore, we have proposed two algorithms to response to one of the principal requests of P2P applications’ users, which is to preserve the anonymity and security of the resource requester and the responder while providing the same light-weighted data lookup