Accelerated transmission in peer-to-peer network

The design and evaluation of accelerated transmission （AT） systems in peer-to-peer networks for data transmission are introduced. Based on transfer control protocol （TCP） and peer-to-peer （P2P） substrate networks, AT can select peers of high performance quality, monitor the transfer status of each peer, dynamically adjust the transmission velocity and react to connection degradation with high accuracy and low overhead. The system performance is evaluated by simulations, and the interrelationship between network flow, bandwidth utilities and network throughput is analyzed. Owing to the collaborative operation of neighboring peers, AT accelerates the process of data transmission and the collective network performance is much more satisfactory.

A novel constant degree and constant congestion DHT scheme for peer-to-peer networks

Degree, diameter and congestion are important measures of distributed hash table (DHT) schemes for peer-to-peer networks. Many proposed DHT schemes are based on some traditional interconnection topologies and the Kautz graph is a topology with good properties such as optimal network diameter. In this paper, FissionE, a novel DHT scheme based on the Kautz graph, is proposed. FissionE is the first constant degree and O(logN) diameter DHT scheme with (1+o(1))-congestion. FissionE shows that the DHT scheme with constant degree and constant congestion can achieve O(logN) diameter, which is better than the lower bound ? (N1/d) conjectured before. The average degree of FissionE is 4 and the diameter is 2*log2N, and the average routing path length is about log2N. The average path length of FissionE is shorter than CAN or Koorde with the same degree when the P2P network is large scale.

Targeted Local Immunization in Scale-Free Peer-to-Peer Networks

The power-law node degree distributions of peer-to-peer overlay networks make them extremely robust to random failures whereas highly vulnerable under intentional targeted attacks. To enhance attack survivability of these networks, DeepCure, a novel heuristic immunization strategy, is proposed to conduct decentralized but targeted immunization. Different from existing strategies, DeepCure identifies immunization targets as not only the highly-connected nodes but also the nodes with high availability and/or high link load, with the aim of injecting immunization information into just right targets to cure. To better trade off the cost and the efficiency, DeepCure deliberately select these targets from 2-local neighborhood, as well as topologically-remote but semantically-close friends if needed. To remedy the weakness of existing strategies in case of sudden epidemic outbreak, DeepCure is also coupled with a local-hub oriented rate throttling mechanism to enforce proactive rate control. Extensive simulation results show that DeepCure outperforms its competitors, producing an arresting increase of the network attack tolerance, at a lower price of eliminating viruses or malicious attacks.

SKY:Efficient peer-to-peer networks based on distributed Kautz graphs

Many proposed P2P networks are based on traditional interconnection topologies. Given a static topology, the maintenance mechanism for node join/departure is critical to designing an efficient P2P network. Kautz graphs have many good properties such as constant degree, low congestion and optimal diameter. Due to the complexity in topology maintenance, however, to date there have been no effective P2P networks that are proposed based on Kautz graphs with base ~ 2. To address this problem, this paper presents the ＂distributed Kautz （D-Kautz） graphs＂, which adapt Kautz graphs to the characteristics of P2P networks. Using the D-Kautz graphs we further propose SKY, the first effective P2P network based on Kautz graphs with arbitrary base. The effectiveness of SKY is demonstrated through analysis and simulations.

Super-proximity routing in structured peer-to-peer overlay networks

Peer to Peer systems are emerging as one of the most popular Internet applications. Structured Peer to Peer overlay networks use identifier based routing algorithms to allow robustness, load balancing, and distributed lookup needed in this environment. However, identifier based routing that is independent of Internet topology tends to be of low efficiency. Aimed at improving the routing efficiency, the super proximity routing algorithms presented in this paper combine Internet topology and overlay routing table in choosing the next hop. Experimental results showed that the algorithms greatly improve the efficiency of Peer to Peer routing.

TSPN: Term-Based Semantic Peer-to-Peer Networks

In this paper, we propose Term-based Semantic Peerto-Peer Networks （TSPN） to achieve semantic search. For each peer, TSPN builds a full text index of its documents. Through the analysis of resources, TSPN obtains series of terms, and distributes these terms into the network. Thus, TSPN can use query terms to locate appropriate peers to perform semantic search. Moreover, unlike the traditional structured P2P networks, TSPN uses the terms, not the peers, as the logical nodes of DHT. This can withstand the impact of network chum. The experimental results show that TSPN has better performance compared with the existing P2P semantic searching algorithms.

Reliable Content Distribution in P2P Networks Based on Peer Groups

Peer-to-Peer (P2P) networks are highly dynamic systems which are very popular for content distribution in the Internet. A single peer remains in the system for an unpredictable amount of time, and the rate in which peers enter and leave the system, i.e. the churn, is often high. A user that is obtaining content from a selected peer is frequently informed that particular peer is not available anymore, and is asked to select another peer, or will have another peer assigned, often without enough checks to confirm that the content provided by the new peer presents the same quality of the previous peer. In this work we present a strategy based on group communication for transparent and robust content access in P2P networks. Instead of accessing a single peer for obtaining the desired content, a user request is received and processed by a group of peers. This group of peers, called PCG (Peer Content Group) provides reliable content access in sense that even as members of the group crash or leave the system, users continue to receive the content if at least one group member remains fault-free. Each PCG member is capable of independently serving the request. A PCG is transparent to the user, as the group interface is identical to the interface provided by a single peer. A group member is elected to serve each request. A fault monitoring component allows the detection of member crashes. If the peer is serving request crashes, another group member is elected to continue providing the service. The PCG and a P2P file sharing applications were implemented in the JXTA platform. Evaluation results are presented showing the latency of group operations and system components.

“We Are Only as Strong as We Are United, as Weak as We Are Divided” a Dynamic Analysis of the Peer Support Networks in the Harry Potter Books

This research studied the concept of enacted peer support during adolescence by means of the Harry Potter Series. A network approach was used. Results indicated the importance of reciprocity and transitivity for enacted peer support during adolescence. Contrary to our expectations, gender, age and personality traits did not affect enacted peer support. No homophily effects based on gender and age were detected. However, students were found to be more supportive of students with similar personality traits. We hope this study adds to the current knowledge on peer support in adolescence and promotes the use of social theories and methods in literacy research.

Performance of Fixed Channel Assignment for Uplink Transmission and Direct Peer-to-Peer Communications in Multihop Cellular Networks

In this paper, we propose a clustered multihop cellular network （cMCN） architecture and study its performance using fixed channel assignment （FCA） scheme for uplink transmission. The proposed cMCN using FCA can be applied with some reuse factors. An analytical model based on Markov chain is developed to analyze its performance and validated through computer simulation. And then, we implement direct peer-to-peer communication （DC） in cMCN by considering more reasonable conditions in practice. DC means that two calls communicate directly instead of going through base stations. The results show that cMCN with FCA can reduce the call blocking probability significantly as compared with the traditional single-hop cellular networks with FCA and can be further reduced by using DC.

分布式Peer-to-Peer网络Gnutella模型研究

计算机对等联网(peer-to-peernetwork,P2P)技术是目前新一代网络技术研究的活跃领域,而P2P网络模型研究是P2P网络技术研究的重要环节。该文着重介绍了Gnutella网络模型的体系结构及工作原理,分析了其优缺点。并对其未来发展改进前景进行了展望。

Peer-to-Peer网络模型研究

计算机对等联网(peer-to-peernetwork,P2P)技术是目前新一代网络技术研究的活跃领域,而P2P网络模型研究是P2P网络技术研究的重要环节。该文分析了目前两种流行P2P网络模型的不足,通过在P2P网络中引入集中和分级目录概念,根据资源内容建立不同的层次结构,提出了一种新型P2P网络模型。

Peer-to-Peer网络中安全对等组的实现

计算机对等联网(peer-to-peernetwork,P2P)技术是目前流行于国际网络技术研究领域的一个热点,而安全问题则是P2P网络通信研究中的重要课题。通过应用JXTA技术,文章着重阐述了在P2P网络中实现安全对等组的方法及其工作机制,并在JavaTM2平台上予以实现。

基于Peer-to-Peer网络的JXTA技术研究

计算机对等联网(peer-to-peernetwork,P2P)技术是一项新型网络应用技术,而JXTA技术是由Sun微系统公司推出的一项致力于为P2P应用提供所需基础服务的新技术。该文着重介绍了JXTA技术的体系结构和核心协议,分析了其可行性,并对其未来发展前景进行了展望。

Peer-to-Peer文件共享系统的测量研究

Peer-to-Peer(P2P)技术的发展引发了Internet应用模式的变革.为了寻求网络运营商、内容提供商和Internet用户三方共赢的解决方案,必须从他们各自的角度出发对P2P应用进行系统的测量与分析.首先概述了P2P测量的研究内容,并将现有的P2P测量研究划分为P2P拓扑特征的测量、P2P流量特征的测量、P2P可用性的测量3类.在对P2P测量方法进行对比分析之后,详细综述了P2P测量的研究现状,对现有的各种测量方案以及研究成果进行了深入的分析,指出了其中存在的问题和缺陷.最后讨论了P2P测量未来的研究方向.

Peer-to-Peer环境下的信任模型研究

开放、共享、匿名的peer-to-peer网络已经取得了越来越多的应用,无中心时等的特性也吸引了越来越多的用户,但同时也成为了网络攻击者传播恶意内容或病毒的温床。由于其网络中的节点不受约束,节点间存在着自愿的交易行为,因此节点之间的信任很难通过传统网络的机制来制约和建立。本文旨在通过借鉴人类社会网络中的信任关系来建立一种信任模型,通过定义一系列信任的因子,用以制约用户行为,同时为用户寻求服务前提供参考。最后通过和其他信任模型的对比,我们的模型能够有效地激励用户提供反馈,遏制节点的不诚实行为。

一种有效的Peer-to-Peer自适应拓扑进化协议

现有的无结构Peer-to-Peer(P2P)系统缺乏对拓扑公平性的考虑,并且不能对某些节点的恶意行为进行有效的抑制.其主要原因在于构造的拓扑对节点可信度的不敏感性,忽略了节点在不同领域中可信度的区别.据此,首先给出了基于领域的P2P信任模型的定义,然后在此基础上提出了一种针对无结构化P2P网络的自适应拓扑进化协议.该协议可以针对具体的领域进行拓扑进化,使得领域内的高可信节点占据相应领域拓扑的有利位置,低可信节点处于不利位置,从而体现拓扑的公平性.该协议同时能够对节点的恶意行为进行有效的抑制,并具有激励性质,鼓励节点提供更好的服务,以获得更高的回报率.分析和仿真结果表明,该协议较之现有协议,在拓扑的有效性和安全性等方面有较大的提高.

Peer-to-Peer体系结构及一种新型对等实体模型

对等网络结构也许会在Internet的变革中具有划时代的意义,这预示着它将为各种形式的网络运用提供了一个坚实基础。但是,基于对等网络结构的应用同时也将给开发者以巨大挑战,甚至让一些人认为这种结构是不可实现的。本文探讨了一个可实现的、健壮的对等网络结构所需要素,并给出一种新型对等实体模型的构想。

Internet中Peer-to-Peer应用流量测量与分析

Peer to Peer网络(简称p2p)作为一种新型的覆盖网络引起了越来越多研究者的兴趣。本文介绍了在我国进行的骨干互联网上p2p网络流量测量。与现有国外研究不同,本文的数据来源于核心路由器,因此克服了它们的缺陷。其研究集中在汇聚流中的3个周期性尖峰群、不同主机发送或接收流量的重尾分布、p2p流量的长相关特性以及提出了ADTE的估计方法来区分信令和数据流量。本文的研究也显示出Napster在p2p流中占大部分,这暗示着超级节点和阶层式拓扑较纯p2p结构潜在的优势。同时,观察到在我国p2p的流量仅占Internet总流量的1%弱,这个值跟国外的数据有很大区别。我们分析了其中的原因并希望该结论为我国p2p软件的发展提供参考。

基于Region的多层结构Peer-to-Peer网络模型与搜索算法研究

以小世界模型为理论基础,以 Region 为基本逻辑管理单位,按用户需求和共享目的组织 Region。提出了基于 Region 的多层结构 Peer-to-Peer 网络模型和构造规则,给出了 Region 的划分策略和数学模型,证明了模型的正确和合理性;对模型中的层和域、中心节点、普通节点和汇聚点进行了明确的定义,给出了节点加入、离开、中心节点选取策略和算法描述;使定位某种服务的工作量和查询范围从网络中的所有结点数降低到 Region 的节点数,有效地防止了恶意请求引发的洪,网络系统开销为常数。模拟分析表明,该模型可有效解决可扩展性、性能与效率不高问题,且网络规模越大,其综合性能的优越性越明显,因此,模型是合理有效的。

基于Gnutella协议的分布式Peer-to-Peer网络连接管理策略及改进研究

在分析Gnutella网络协议、消息传播和连接管理机制的基础上,提出了基于F-Measure算法的网络连接管理策略,在算法中引入了一个重要的指标F-Measure参数f:丢弃连接后消息的到达率,当网络过载时,选f值最大的连接断开;通过对Gnutella网络中的消息分类和设定优先级,建立缓冲时间机制保存丢弃连接上的重要信息,以最小的代价维护网络的鲁棒性;在应用层上采用Zig-Zag算法进行数据流控制,辅助F-Measure算法进行连接管理,有效地控制了Gnutella网络产生的请求Flood,使网络的连接管理具体数据化。最后,对F-Measure算法进行了性能分析和模拟。