A measurement study supporting P2P file-sharing community models

Knowledge of emergent properties of existing peer-to-peer file-sharing communities can be helpful for the design and implementation of innovative peer-to-peer protocols/services that exploit autonomicity, self-configuration, resilience, scalability, and performance. It is well known that the performance of this class of peer-to-peer applications depends on several parameters that represent the topological structure of the overlay network, the users’ behavior, and resource dynamics. Estimation of these parameters is difficult, but it is crucial for analytical models as well as for realistic simulation of peer-to-peer applications.In this paper, we present an active measurement-based study designed to glean insights on the above parameters within the Gnutella network. The measurement software that we developed is able to collect topological information about the overlay network topology in a few minutes; in a second step, it contacts the users discovered during the topological measurement in order to acquire a novel dataset regarding the shared resources.     

MBone provides audio and video across the Internet

Researchers have produced the Multicast Backbone (MBone), which provides audio and video connectivity from outer space to under water-and virtually everyplace in between. MBone is a virtual network that has been in existence since early 1992. It originated from an effort to multicast audio and video from meetings of the Internet Engineering Task Force. Today. hundreds of researchers use MBone to develop protocols and applications for group communication. Multicast provides one-to-many and many-to-many network delivery services for applications such as videoconferencing and audio where several hosts need to communicate simultaneously. This article describes the network concepts underlying MBone, the importance of bandwidth considerations, various application tools, MBone events, interesting MBone uses, and provides guidance on how to connect your Internet site to the MBone     

基于用户行为聚类的搜索

因特网的飞速发展,网络资源呈爆炸式的增长。信息检索是人们上网的主要目的之一。目前的信息检索领域有许多检索方法与检索工具,为用户检索信息提供了许多途径。但如何利用搜索引擎实现更快更精确的搜索已经成为这一领域的研究热点。在研究现有的几种搜索引擎的基础上,提出了一种基于用户行为聚类的搜索引擎。通过分析不同的用户行为将搜索用户聚类成不同的用户组,为每组用户返回其喜欢的结果,优化查询结果。     

打造高效、有序、可控的网络管理环境

随着信息技术的快速发展,网络应用更新换代频繁,新兴应用不断涌现.在给生活和工作带来便捷的同时,互联网也对上网行为管理带来了新的挑战.本文着力于论述如何对现有网络采取有效的上网管理手段,研究上网行为管控的先进技术方案,如何避免管理漏洞和提高网络带宽资源的价值.     

Smart City and IoT

The new Internet of Things (IoT) applications are enabling Smart City initiatives worldwide. It provides the ability to remotely monitor, manage and control devices, and to create new insights and actionable information from massive streams of real-time data. The main features of a smart city include a high degree of information technology integration and a comprehensive application of information resources. The essential components of urban development for a smart city should include smart technology, smart industry, smart services, smart management and smart life. The Internet of Things is about installing sensors (RFID, IR, GPS, laser scanners, etc.) for everything, and connecting them to the internet through specific protocols for information exchange and communications, in order to achieve intelligent recognition, location, tracking, monitoring and management. With the technical support from IoT, smart city need to have three features of being instrumented, interconnected and intelligent. Only then a Smart City can be formed by integrating all these intelligent features at its advanced stage of IOT development. The explosive growth of Smart City and Internet of Things applications creates many scientific and engineering challenges that call for ingenious research efforts from both academia and industry, especially for the development of efficient, scalable, and reliable Smart City based on IoT. New protocols, architectures, and services are in dire needs to respond for these challenges. The goal of the special issue is to bring together scholars, professors, researchers, engineers and administrators resorting to the state-of-the-art technologies and ideas to significantly improve the field of Smart City based on IoT.     

A network infrastructure for IP mobility support in metropolitan areas

The original design of the Internet and its underlying protocols did not anticipate users to be mobile. With the growing interest in supporting mobile users and mobile computing, a great deal of work is taking place to solve this problem. For a solution to be practical, it has to integrate easily with existing Internet infrastructure and protocols, and offer an adequate migration path toward what might represent the ultimate solution. In that respect, the solution has to be incrementally scalable to handle a large number of mobile users and wide geographical scopes, and well performing so as to support all application requirements including voice and video communications and a wide range of mobility speeds. In this paper, we present a survey of the state-of-the-art and propose a scalable infrastructure to support mobility in Internet protocol networks. In that respect, we exploit local area network (LAN) technologies to create the network infrastructure necessary to offer connectivity to mobile users across any geographical area (building, campus and metropolis). The intrinsic properties of LAN technologies and their underlying protocols, namely flat address space, transparent learning and low complexity renders this solution particularly cost effective for supporting user mobility. In particular, we propose a network topology and a set of protocols that render the infrastructure scalable to a large geographical area and many users.     

基于区块链的网络安全体系结构与关键技术研究进展

随着互联网技术的不断演进与用户数量的“爆炸式”增长,网络作为一项基础设施渗透于人们生存、生活的各个方面,其安全问题也逐渐成为人们日益关注的重点.然而,随着网络规模的扩大以及攻击者恶意行为的多样化、复杂化,传统网络安全体系架构及其关键技术已经暴露出单点信任、部署困难等诸多问题,而具备去中心化、不可篡改等特性的区块链技术为网络安全所面临的挑战提供了新的解决思路.本文从网络层安全、应用层安全以及PKI安全三方面对近几年基于区块链的网络安全体系结构与关键技术研究进行梳理,并将区块链的作用归类为真实存储、真实计算、真实激励三种情形.针对区块链的具体应用领域,本文首先介绍了该领域的安全现状,然后对区块链的具体应用研究进行了介绍,并分析了区块链技术在该领域所存在的优势.本文最后结合现有的解决思路对未来区块链应用中所需要注意的隐私问题、可扩展性问题、安全问题以及区块链结构演进的方向进行了分析,并对未来基于区块链的网络安全体系结构与关键技术研究进行了展望.     

An architectural approach towards Future Media Internet

Internet is the most important information exchange means nowadays and has become the core communication environment, not only for business relations, but also for social and human interaction. Yet, the immense success of Internet has created even higher hopes and expectations for new immersive and real-time applications and services. However, there are no guarantees that the current Internet will be able to support them. To face the new requirements coming from these new applications and services, several architectural approaches have been proposed. Evolutionary and clean-slate approaches, based on content-centric architectures, have been proposed for meeting new requirements regarding media. This paper highlights the main architectural functions and presents a revolutionary protocol stack and a holistic architectural approach that targets Future Media Internet (FMI). Among the architectural functions and the holistic approach, the paper presents solutions to overcome the current content delivery limitations, moving intelligence in the network and converting it into a content oriented/centric network, that goes well beyond current CDNs; supporting the functionalities for producing, publishing, caching, finding and consuming content; and a novel Future Media Internet protocol stack and network architecture.     

手机位置信息的保护和利用

高速发展的智能手机和无线网络将互联网推向了移动互联网的世界,众多手机操作系统和应用软件开发公司为了获取更多的资源,肆无忌惮地对手机用户的位置信息进行收集,广大用户如何对手机位置信息进行保护,以及如何利用好这些位置信息,本文中将进行探讨。     

Internet中的多媒体快速查询

随着多媒体技术和网络技术的发展以及在教育中的广泛应用,使得基于互联网的网络教育方式逐渐成为学习者获取知识、实现终身学习的重要手段。Internet的飞速发展,使网络上的信息呈指数增长,其内容丰富,种类之繁多堪称世界上最大的图书馆,如何有效地查询到符合用户兴趣的多媒体资料,关系到用户能否在教学中充分地利用这个巨大的信息资源的问题。     

Ontology-mediated integration of intranet Web services

The recent adoption of XML-based Web services standards has further integrated distributed resources with open Internet protocols at the software service level. Developers are moving beyond simply extending Web resource access and are making a sustained effort to tap into the depth of mutual understanding that can be culled from the Web's diverse content. Ultimately, they will organize this information conceptually and place it in the semantic Web's framework. For end users, the vast increase in available services these initiatives provide can imply either more freedom or more chaos. This flood of options raises the vital issue of how emerging technologies can help to automate the manual operations individual applications require. The smart office task automation framework uses Web services, an ontology, and agent components to create an integrated information-service platform that provides user-centric support for automating intranet office tasks.     

Security at the Internet layer

The Internet Engineering Task Force is standardizing security protocols (IPsec protocols) that are compatible with IPv6 and can be retrofitted into IPv4. The protocols are transparent to both applications and users and can be implemented without modifying application programs. The current protocol versions were published as Internet drafts in March 1998. The article overviews the proposed security architecture and the two main protocols-the IP Security Protocol and the Internet Key Management Protocol-describes the risks they address, and touches on some implementation requirements. IPsec's major advantage is that it can provide security services transparently to both applications and users. Also, the application programs using IPsec need not be modified in any way. This is particularly important when securing application programs that are not available in source code, which is common today. This transparency sets IPsec apart from security protocols that operate above the Internet layer. At present, IPsec is likely to be used in conjunction with and complemented by other security technologies, mechanisms, and protocols. Examples include firewalls and strong authentication mechanisms for access control, and higher layer security protocols for end-to-end communication security. In the near future, however, as virtual private networking and corporate intranets and extranets mature, IPsec is likely to be deployed on a larger scale     

Internet服务管理技术综述

1 服务与服务的分类经常提到服务这个概念,那么到底什么是服务呢?文[1]对服务进行了定义:服务就是服务提供方向一个或多个所服务的用户提供的一组实际能力。为研究之便,我们将服务分成两类:一类是传输服务,另一类是应用服务。这两种服务并不完全独立,它们是相互依存的,其中传输服务是应用服务的基础与保证,而应用服务是对传输服务的一种增值与体现。应用     

层次式交换网络——未来Internet的一种新框架

1 背景新的应用需求和通讯技术的进步是驱动网络体系结构和网络协议发展的主要力量。自1995年开始,Internet数据流量以每年超过100％的速度增长,估计2002年,数据业务量将超过话音业务量,并在未来三年里将占总业务量的90％。同时,数据应用也从传统应用(电子邮件、文件传输、WWW等)向实时多媒体应用(IP电话、视频会议、VOD、交互游戏、虚拟现实、远程医疗和远程教育等)迅速发展,要求     

Context-aware control of user-centric virtual networks: Centralized vs distributed approaches

Recently, the Internet has been overrun by a diversity of devices, applications, technologies, and Internet users with increasingly demanding personal preferences. Due to the explosive growth of Internet usage, the quantity of context information available in networking environments is also growing rapidly, triggering research for novel architectures and protocols that are enriched or personalized based on the particular features and dynamics of such information.This article describes a virtualized architecture that splits a physical network infrastructure into a set of logical networks (or Virtual Networks – VNs) configured to meet the particular context needs of their attached users (in terms of, e.g., price, security or services’ quality). Since this architecture can be driven by volatile context needs of highly mobile users, we also present the signaling mechanisms to create, extend and remove VNs in response to user context dynamics and mobility, which can be performed in a centralized or distributed way. Further, we define and evaluate context-aware metrics to configure a VN, and discover and select VNs to assign to users or network paths.The evaluation of the proposed approach shows that distributed approaches allow the fast discovery and adaptation of VNs, at the cost of a slightly larger overhead than centralized approaches when the context dynamics are too high. We also assess the impact of considering distinct levels of knowledge distribution and user context dynamics on the design and behavior of several processes for user association and VN control. Finally, we observe that context-driven VN discovery and resource-aware path selection schemes outperform the ones that, respectively, flood the network with VN discovery requests or use shortest path-based strategies to adapt VNs.     

Increasing application accessibility through Java

Java has begun to open up new possibilities for accessing applications on the Web. With Java, developers can write applications as applets and insert them into Web pages. The user can then retrieve and execute them with local computing resources. We show how developers can use this feature to create a network computing platform that lets Web users share applications not specifically devised for network use, including those that are computationally intensive. With our approach, the network is not involved as long as the user executes operations on the graphical interface, which is executed locally on the client. Only when users require some computational response from the server do they need to access it. Access is straightforward; authorized users can access the application from any node connected with the Internet as long as they have a Java-enabled Web browser. We have used used one such network computing platform to port an existing tool and develop a new application     

An overview of anonymity technology usage

Anonymity technologies enable Internet users to maintain a level of privacy that prevents the collection of identifying information such as the IP address. Understanding the deployment of anonymity technologies on the Internet is important to analyze the current and future trends. In this paper, we provide a tutorial survey and a measurement study to understand the anonymity technology usage on the Internet from multiple perspectives and platforms. First, we review currently utilized anonymity technologies and assess their usage levels. For this, we cover deployed contemporary anonymity technologies including proxy servers, remailers, JAP, I2P, and Tor with the geo-location of deployed servers. Among these systems, proxy servers, Tor and I2P are actively used, while remailers and JAP have minimal usage. Then, we analyze application-level protocol usage and anonymity technology usage with different applications. For this, we preform a measurement study by collecting data from a Tor exit node, a P2P client, a large campus network, a departmental email server, and publicly available data on spam sources to assess the utilization of anonymizer technologies from various perspectives. Our results confirm previous findings regarding application usage and server geo-location distribution where certain countries utilize anonymity networks significantly more than others. Moreover, our application analysis reveals that Tor and proxy servers are used more than other anonymity techniques.     

Embedded Internet环境下TCP/IP协议簇的约简

基于 Em bedded Internet技术下 ,为了实现非 Internet设备信息的共享和访问 ,作者对 TCP/ IP协议簇进行系统的研究 ,提出在设备中嵌入 thin TCP/ IP协议栈并使其能够实现与网络的透明互联 .对 TCP/ IP协议簇进行尽最大可能的约简而不使其失去标准和相应的机制 ,从而可以利用 TCP/ IP协议在设备与 Internet之间建立通讯联系 ,真正把设备纳入到网络的管理范围 ,实现设备的网络化和智能化管理 .设备中嵌入 TCP/ IP协议的实现为工业生产自动化系统和智能家电的网络化和智能化管理提供可靠的技术支持     

Building Distributed Context-Aware Applications

Context-aware applications gather information from sensors about their users and operating environment. Sensor handling is a complicated issue that makes it hard and time-consuming to develop context-aware applications. This paper shows how dynamic discovery protocols can be employed to deal with the physical distribution of sensors and the need to share sensors between many applications. We report on our experiences from building a position-aware application using the dynamic discovery protocol that is part of the Jini software infrastructure for distributed systems.