P2P Content Distribution Systems Research Articles

Survey of Network Coding Based P2P File Sharing in Large Scale Networks

Peer-to-peer (P2P) content distribution and file sharing systems aim to facilitate the dissemination of large files over unreliable networks. Network coding is a transmission technique that has captured the interest of researchers because of its ability to increase throughput and robustness of the network, and decrease the download time. In this survey paper, we extensively summarize, assess, compare, and classify the most recently used techniques to improve P2P content distribution systems performance using network coding. To the best of our knowledge, this survey is the first comprehensive survey that specifically focuses on the performance of network coding based P2P file sharing systems.

Super Generation Network Coding for Peer-to-Peer Content Distribution Networks

In peer-to-peer (P2P) content distribution systems, network coding is known as a helpful method for increasing the content availability, accelerating the download process, and robustness against churn. Originally, dense network coding (DNC) has been proposed and theoretically considered as an optimal solution. However, due to its huge computational overhead, it is not viable for real-world systems. Subsequently, sparse, generations, and overlapped generations network coding schemes are proposed as possible alternatives but at reduced performance compared to that provided by the DNC. Further in this article, an improved applicable network coding scheme for P2P content distribution systems referred to therein as Super Generation Network Coding (SGNC) is proposed. SGNC maximizes the generation size so that it is as close as possible to the optimal size without adding computational overhead. Theoretical analysis and experimental work show that SGNC outperforms classical and all previous coding based schemes for P2P content distribution systems in terms of content availability, download time, overhead, and decodability for all piece scheduling policies.

PCLNC: A low-cost intra-generation network coding strategy for P2P content distribution

It has been proven that network coding can provide significant benefits to P2P networks. In recent years, many schemes have been designed to provide low-cost network coding strategies for P2P content distribution systems. In this paper, firstly, we propose a low-cost intra-generation network coding strategy. By designing the upper triangular encoding matrix, we can reduce the computational complexity of encoding and decoding. Secondly, a linear dependency detection method for encoded blocks is proposed. We use the postponement strategy and the loop self-checking strategy to reduce the probability of receiving linearly dependent encoded blocks. At last, we simulate the distribution system using the above strategies on the simulator and compare it to other systems. From the simulation results, the performance of our system is better than that of the other two systems. Taking the average download time as an example, the average download time of our system is 21.0% and 3.17% lower than other schemes respectively, which effectively improves the distribution efficiency.

Multipath network coding and multicasting for content sharing in wireless P2P networks: A potential game approach

Motivated by the popularity of the peer to peer (P2P) content sharing over internet and the development of wireless device to device (D2D) communications, this paper considers the problem of delivering K different contents to D destinations from N sources in wireless networks. Traffic in opposite directions over two wireless hops can utilize the advantage of network coding (NC) in order to decrease the number of transmissions used. We call such coded hops as “NC-links”. On the other hand, the multicast (MC) links can transmit data to several nodes at the same time, also yielding the improvement of the transmissions efficiency. However, there exists a certain level of ambiguity regarding how to coordinate NC and MC to improve the file sharing performance in wireless P2P content distribution systems. Considering both NC and MC gains, we investigate the content traffic splitting using a potential game model. Subsequently, we identify the equilibrium solution to this game and develop a two-level distributed control algorithm that allows each destination to select the source and split the traffic so as to adjust the content traffic based on the potential function in a distributed way. Through theoretical analysis and simulation results, we show that the proposed scheme is stable and effective.

PSUM: Peer-to-peer multimedia content distribution using collusion-resistant fingerprinting

The use of peer-to-peer (P2P) networks for multimedia distribution has spread out globally in recent years. The mass popularity is primarily driven by cost-effective distribution of content, also giving rise to piracy. An end user (buyer/peer) of a P2P content distribution system does not want to reveal his/her identity during a transaction with a content owner (merchant), whereas the merchant does not want the buyer to further distribute the content illegally. To date, different P2P distribution systems have been proposed that provide copyright and privacy protection at a cost of high computational burden at the merchant׳s and/or at the buyer׳s end and thus, making these systems impractical. In this paper, we propose PSUM, a P2P content distribution system which allows efficient distribution of large-sized multimedia content while preserving the security and privacy of merchants and buyers. The security of PSUM is ensured by using an asymmetric fingerprinting protocol based on collusion-resistant codes. In addition, PSUM enables buyers to obtain digital contents anonymously, but this anonymity can be revoked as soon as he/she is found guilty of copyright violation. The paper presents a thorough performance analysis of PSUM, through different experiments and simulations, and also analyzes several security compromising attacks and countermeasures.

Framework for preserving security and privacy in peer-to-peer content distribution systems

The use of peer-to-peer (P2P) networks for multimedia distribution has spread out globally in recent years. The mass popularity is primarily driven by efficient distribution of content, also giving rise to piracy. An end user (buyer) of a P2P content distribution system does not want to reveal his/her identity during a transaction with a content owner (merchant), whereas the merchant does not want the buyer to further distribute the content illegally. Therefore, there is a strong need for a content distribution mechanism over P2P networks that do not pose security and privacy threats to the copyright holders and end users, respectively. The existent systems for copyright and privacy protection employ cryptographic mechanisms at a cost of high computational burden which makes these systems impractical to distribute large sized files, such as music albums or movies. In this paper, we propose and analyze a P2P content distribution system which allows efficient distribution of large-sized content while preserving the security and privacy of merchants and buyers, respectively. Our proposed framework is able to resolve the problems of piracy tracing, buyer frameproofness, collusion resistance, dispute resolution and buyer’s anonymity. We have carried out simulations to evaluate the performance of our framework in terms of imperceptibility, robustness, throughput and content delivery costs. The experimental results confirm that the proposed framework provides an efficient solution to copyright infringement issues over P2P networks, reducing the multimedia file sizes as much as five times on average, while protecting the end users’ privacy and anonymity.

Strategies of collaboration in multi-swarm peer-to-peer content distribution

In modern Peer-to-Peer (P2P) content distribution applications, multiple swarms typically exist, each corresponding to the dissemination of one content among interested peers. A common design in the existing P2P applications is to allow peers in one swarm to help each other, while different swarms are only coupled when sharing the upload bandwidth at the dedicated content servers/publishers. In recent years, a number of proposals have emerged which advocate inter-swarm collaboration and resource sharing, where peers in one swarm may contribute their storage and bandwidth resources to help peers in the swarm of another content. Such inter-swarm collaboration can improve content availability and optimize resource utilization in the entire system, at the cost of additional overhead for content preloading and inter-swarm coordination. This paper presents a survey of studies on effective inter-swarm collaboration mechanisms in the existing literature. This paper first discusses strategies of collaboration in P2P file sharing applications, and then presents multi-channel collaborative design for P2P live and Video-on-Demand (VoD) streaming. In particular, this paper elaborates our recent design of collaboration strategies among multiple streaming channels in a P2P VoD system, and shows that the server cost can be reduced by up to 25% while high streaming qualities are guaranteed in the entire system, even during extreme scenarios such as unexpected flash crowds. This paper also discusses representative approaches to implement inter-swarm collaborations in various P2P content distribution systems.

An Approach to Continuous Queries in Unstructured Overlays (Coquos)

The current peer-to-peer (P2P) content distribution systems are running by their simple on-demand content discovery mechanism. The utility of these systems can be improved by incorporating two capabilities, first a mechanism through which peers can register their long term interests with the network so that they can be continuously notified of new data items, and second one is the peers to advertise their contents. Although researchers have proposed a few unstructured overlay-based publish-subscribe systems that provide the above capabilities, most of these systems require complex indexing and routing schemes, which not only make them highly complex but also gives less flexible on propagate the queries around transient peers. This paper argues that for many P2P applications, implementing full-fledged publish-subscribe systems is an complex task. For these applications, we study the alternate continuous query paradigm, which is a best-effort service providing the above two capabilities. we present a scalable and effective middleware, called CoQUOS stands for Continious queries in Unstructured Overlays for supporting continuous queries in unstructured overlay networks. Besides being independent of the overlay topology, CoQUOS preserves the simplicity and flexibility of the unstructured P2P network. Index Terms: Peer-to-peer networks, Continuous queries, Publish-subscribe systems, Random walk. I. Introduction: UNSTRUCTURED peer-to-peer (P2P)-based content/resource sharing platforms such as Gnutella and Kazaa have experienced excellent growths in the past days. The popularity of unstructured P2P networks can be based on the simplicity of their designs and their flexibility towards transient node population. Searching in these networks is essentially performed by circulating query messages in an ad-hoc manner and probing individual peer nodes. The current unstructured P2P content distribution systems suffer from certain serious limitations. One such limitation is their simple-on demand mechanism for content discovery. Peers in these systems discover data items by circulating queries within the overlay network. A peer receiving a query responds back to the initiating node if it has any matching content. Upon processing a query, the recipient node removes it from its local buffers1. Thus, a query expires after it completes its circulation within the network. In other words, the network forgets the queries once they have completed their circulation. For clarity purpose called this as a ad hock query model , and we refer to the queries as ad hoc queries. The ad hoc query model suffers from two main short comings First, an ad hoc query is only capable of searching and retrieving content that exists in the P2P network at the time the query was issued. In this scenario, the only way for a peer to discover newly added data items would be to repeatedly issue the same query. This is not desirable, since it creates unnecessary traffic within the network. Second, P2P systems that are purely based on the ad hoc query -model provide no support for peers to advertise or announce the data items they own to other interested peers. Advertisements are important for P2P applications where peers advertise their content. The above are shortcomings render the ad hoc query model .The many advanced P2P applications suffered from above two drawbacks. For handling the above situation we use a naive approach for tackling this problem would be to send advertisements to large subsets of peers through Flooding. However, this approach is unviable. When heavy messaging overheads, this scheme could gives the peers with unwanted advertisements. To address the above limitations we use well-studied paradigm of publish-subscribe (pub-sub) Systems is a possible approach to address the above limitations. The pub-sub involves intricate indexing and routing mechanisms . To overcome the above problem we present a scalable and effective middleware, called CoQUOS stands for Continious queries in Unstructured Overlays for supporting continuous queries in unstructured overlay. 1.1.) Paper Contributions: The diffculties in implementing pub-sub systems on top of unstructured overlays can be attributed to the inherent mismatch between the design requirements of pub-sub systems and the very nature of unstructured P2P systems. The pub-sub model provides weaker guarantees and individual implementations of may not provide and notification guarantees are weaker due to system failures or churn.

피어 투 피어 네트워크에서 스워밍 기법을 위한 보안 프로토콜

With fast deployment of high-speed networks and various online services, the demand for massive content distribution is also growing fast. An approach that is increasingly visible in communication research community and in industry domain is peer-to-peer (P2P) networks. The P2P swarming technique enables a content distribution system to achieve higher throughput, avoid server or network overload, and be more resilient to failure and traffic fluctuation. Moreover, as a P2P-based architecture pushed the computing and bandwidth cost toward the network edge, it allows scalability to support a large number of subscribers on a global scale, while imposing little demand for equipment on the content providers. However, the P2P swarming burdens message exchange overheads on the system. In this paper, we propose a new protocol which provides confidentiality, authentication, integrity, and access control to P2P swarming. We implemented a prototype of our protocol on Android smart phone platform. We believe our approach can be straightforwardly adapted to existing commercial P2P content distribution systems with modest modifications to current implementations.

Interaction patterns between P2P content distribution systems and ISPs

Peer-to-peer (P2P) content distribution systems are a major source of traffic in the Internet, but the application layer protocols they use are mostly unaware of the underlying network in accordance with the layered structure of the Internet's protocol stack. Nevertheless, the need for improved network efficiency and the business interests of Internet service providers (ISPs) are both strong drivers toward a cross-layer approach in peer-to-peer protocol design, calling for P2P systems that would in some way interact with the ISPs. Recent research shows that the interaction, which can rely on information provided by both parties, can be mutually beneficial. In this article we first give an overview of the kinds of information that could potentially be exchanged between the P2P systems and the ISPs, and discuss their usefulness and the ease of obtaining and exchanging them. We also present a classification of the possible approaches for interaction based on the level of involvement of the ISPs and the P2P systems, and we discuss the potential strengths and the weaknesses of these approaches.

Is playing-as-downloading feasible in an eMule P2P file sharing system?

Peer-to-peer (P2P) swarm technologies have been shown to be very efficient for large scale content distribution systems, such as the well-known BitTorrent and eMule applications. However, these systems have been designed for generic file sharing with little consideration of media streaming support, and the user cannot start a movie playback before it is completely downloaded. The playing-as-downloading capability would be particularly useful for a downloading peer to evaluate if a movie is valuable to be downloaded, and it could also help the P2P content distribution system to locate and eliminate the polluted contents. In this paper we address this issue by introducing a new algorithm, wish driven chunk distribution (WDCD), which enables the P2P file sharing system to support the video-on-demand (VOD) function while keeping the P2P native downloading speed. A new parameter named next-play-frequency is added to the content chunk to strike a replication balance between downloading and streaming requests. We modify the eMule as the test bed by adding the WDCD algorithm and then verify the prototype implementation by experiments. The experimental results show that the proposed algorithm can keep the high downloading throughput performance of the eMule system with a good playing-as-downloading function.

Improving the Performance of P2P Content Distribution Systems by Choosing Proper Content Providers

Searching mechanisms employed in unstructured overlay networks typically hit multiple peers for the desired content. We propose the use of a simple method that raises the hit rates of unpopular contents and balances the loads by choosing the peer holding the least contents as the provider when multiple candidates exist.

A Hybrid P2P Overlay Network for Non-strictly Hierarchically Categorized Content

In P2P content distribution systems, there are many cases in which the content can be classified into hierarchically organized categories. In this paper, we propose a hybrid overlay network design suitable for such content called Pastry/NSHCC (Pastry for Non-Strictly Hierarchically Categorized Content). The semantic information of classification hierarchies of the content can be utilized regardless of whether they are in a strict tree structure or not. By doing so, the search scope can be restrained to any granularity, and the number of query messages also decreases while maintaining keyword searching availability. Through simulation, we showed that the proposed method provides better performance and lower overhead than unstructured overlays exploiting the same semantic information.