Architecture For Content Distribution Research Articles

Content delivery networks: a bridge between emerging applications and future IP networks

With the rapid development of network applications, the Internet has evolved from a content-based communication infrastructure to a social-based community network. The emerging applications require the Internet to preserve not only the existing advantages of simplicity and scalability, but also demand varying amounts of capability, availability, reliability, flexibility, and differentiated quality of service. Therefore, it is of paramount importance to bridge the gap between these applications and the IP networks which were originally designed and developed for supporting one-size-fits-all functionality. An efficient solution is to build a virtual network on top of a generic IP transport layer in order to provide additional functionality and flexibility. The content delivery networks technique is one of the successful virtual networks rapidly developed over the last decade with the specific advantage of optimizing the Internet. Nowadays, the CDN has become one of the most important parts of the Internet architecture for content distribution. In this article we highlight the innovative technologies in CDNs and present their evolution triggered by ever newer emerging applications. By presenting in-depth discussion about the architecture, challenges, and applications of CDNs, we demonstrate their importance for the future Internet.

A path-traceable query routing mechanism for search in unstructured peer-to-peer networks

Unstructured Peer-to-Peer (P2P) networks have become a very popular architecture for content distribution in large-scale and dynamic environments. Searching for content in unstructured P2P networks is a challenging task because the distribution of objects has no association with the organization of peers. Proposed methods in recent years either depend too much on objects replication rate or suffer from a sharp decline in performance when objects stored in peers change rapidly, although their performance is better than flooding or random walk algorithms to some extent. In this paper, we propose a novel query routing mechanism for improving query performance in unstructured P2P networks. We design a data structure called traceable gain matrix (TGM) that records every query's gain at each peer along the query hit path, and allows for optimizing query routing decision effectively. Experimental results show that our query routing mechanism achieves relatively high query hit rate with low bandwidth consumption in different types of network topologies under static and dynamic network conditions.

Design of HD-quality Streaming Networks for Real-time Content Distribution

Recent advances in storage and networking technology are rapidly changing users' TY viewing patterns. Personal video recorders (PVRs) enable people to watch what they want when they want by recording TV programs into local disks. In addition, PVRs can easily share TV contents over peer-to-peer networks once they are equipped with broadband connections. However, the current broadband bandwidth makes it difficult to support HD-quality TV content streaming on the Internet. In this paper, we propose a novel HD-quality streaming architecture for real-time broadcast content distribution. We develop two efficient scheduling schemes, matching a communication pair and switching/replication for system load-balancing, to further utilize network and disk bandwidth. We also evaluate buffer requirement to continue storing time-shifted programs without missing any broadcast data. By extensive simulation experiments, we show the effect of our proposed schemes and time-shifting policy.

A streaming content distribution network for e‐learning support

To date e‐Learning material has usually been accessed and delivered through a central web server. As the number of users, the amount of information, the frequency of accesses and the volume of data increase, together with the introduction of multimedia streaming applications, a decentralized content distribution architecture is necessary. In this paper we propose the adaptation of the well‐known scalable Content Distribution Networks (CDN) schema for media streaming supported e‐Learning using a novel architecture named COMODIN SCDN (COoperative Media On‐Demand on the InterNet ‐ Streaming Content Distribution Network). COMODIN SCDN utilises surrogates as edge content delivery nodes, incorporates a redirection mechanism able to route requesting clients to the closest copy of the content, encompasses distributed content delivery and management mechanisms to improve the speed, reliability, and scalability of user access to prevent flash‐crowds. Preliminary results in testbeds have shown that COMODIN SCDN increases the efficacy of information distribution through intra and inter‐campus area netwoks. This overlay network will provide learners and educators a scalable, balanced and expeditious access to e‐Learning contents.

Design, implementation, and evaluation of differentiated caching services

With the dramatic explosion of online information, the Internet is undergoing a transition from a data communication infrastructure to a global information utility. PDAs, wireless phones, Web-enabled vehicles, modem PCs, and high-end workstations can be viewed as appliances that "plug-in" to this utility for information. The increasing diversity of such appliances calls for an architecture for performance differentiation of information access. The key performance accelerator on the Internet is the caching and content distribution infrastructure. While many research efforts addressed performance differentiation in the network and on Web servers, providing multiple levels of service in the caching system has received much less attention. It has two main contributions. First, we describe, implement, and evaluate an architecture for differentiated content caching services as a key element of the Internet content distribution architecture. Second, we describe a control-theoretical approach that lays well-understood theoretical foundations for resource management to achieve performance differentiation in proxy caches. An experimental study using the Squid proxy cache shows that differentiated caching services provide significantly better performance to the premium content classes.