Policy-based Diffserv on Internet servers: the AIX approach

The Internet infrastructure must evolve from best-effort service to meet the needs of different customers and applications. With Internet traffic differentiation, service providers can support a range of offerings, such as loss or delay bounds and network bandwidth allocation, to meet different performance requirements. The differentiated services (Diffserv) architecture provides a scalable approach, in which network access (or edge) devices aggregate traffic flows onto provisioned pipes that traverse a streamlined network core. We have identified the key requirements for provisioning Diffserv functions on Internet servers. Based on these requirements, we have implemented, and deployed, a policy-based architecture on IBM's AIX operating system that provides Diffserv services to both QoS-aware and -unaware applications     

一种基于种族分类进化的QoS异构组播路由机制

随着新型网络应用的大量涌现,传统的网络技术已无法满足当前应用在带宽、延迟及出错率等方面的需求,IP over DWDM光互联网以其独特性能优势成为研究热点。基于种族分类进化算法,提出了一种IP over DWDM光互联网服务质量QoS异构组播路由机制。具体地,利用概率论方法处理网络状态参数信息的不确定性;引入模糊数学方法,确定用户对QoS的需求并提供柔性QoS支持;综合考虑网络提供方和用户方的利益,设计公平的带宽定价方法。仿真结果表明,该路由机制获得了良好的综合性能指标,可以有效地解决IP over DWDM光互联网中的柔性QoS异构组播路由选择问题。     

IPv6驻地网部署方案研究

IPv6是在IPv4的基础上提出的,其优越性不只是在带来更多的IP地址,还在安全性、QoS、移动性等方面比IPv4具有更多的优势。现正处于IPv6网络的高速发展阶段,各高校及科研单位分别建立了各自的IPv6网络。提出以某高校的IPv6驻地网建设为例,详细分析了原IPv4校园网网络结构及建设IPv6网络待解决的问题,给出了建设IPv6驻地网采用的具体方案及技术路线。     

RSVP在数字视频网络传输QoS保障中的应用研究

随着网络数字视频的广泛应用，对实时性的要求也变得越来越紧迫。这些应用程序要求因特网协议(IP)能够提供有保证的带宽、较高的优先级以及较低的包丢失率。为了达到这一要求，Internet工程任务组(IETF)开发了一套用于因特网的综合服务的协议和标准。通过资源预留协议(RSVP)来管理网络资源分配以提供不同级别的服务。讨论了怎样将该协议与典型的数字视频网络传输方案相结合，以使现有支持服务质量(QoS)的网络可以提供更为稳定流畅的传输效果。     

CitiTime: a system for rapid creation of portable next-generation telephony services

We present the architecture, design and experimental research prototype implementation of CitiTime, an open system architecture for the rapid development of advanced next-generation telephony services that overcomes some of the limitations of the current closed PSTN architecture and service model. CitiTime allows communication sessions to be set up over the PSTN, the Internet, or a combination of both. Services can be provided by multiple cooperating distributed service providers, some of whom may use third-party software components which can be “plugged in” or even dynamically downloaded from the network as needed. This allows advanced services to be deployed and delivered to users rapidly, a crucial requirement in the increasingly competitive telecommunications services marketplace. CitiTime is built upon an object-oriented call model called Citi Call Control (CCC) which we have defined as a small set of extensions to the standard Java Telephony API (JTAPI) call model. JTAPI is designed primarily for centralized, single provider, call center type applications. Our extensions provide support for multiple, distributed providers as well as advanced services. CCC hides details of underlying call-state management, protocols and hardware from applications. The CitiTime prototype software is currently operational in our laboratory. We briefly describe its current implementation as well as future work to address issues such as fault tolerance.     

An applications perspective into the Future Internet

The building of the Future Internet is well on its way with many research projects and experimental development activities in different parts of the works. However the debate over different approaches is still ongoing. Much of the comparison is concentrating on the different technical capabilities, however, very little effort has been put on finding out how such capabilities will actually be used by the different stakeholders and in particular by users and service providers. Decisions such as whether to take an evolutionary step with TCP/IP, start to use cellular protocols, or develop something new, should be based on realistic and validated user scenarios clearly highlighting what might be needed in the future and indicating a prioritised roadmap. As the Future Internet is needed for supporting new applications and services, it is natural that the requirements for Future Internet should come from the future applications. In this paper, we take a look at a likely future to see what kind of applications can be expected. We then analyse some potential future applications trying to understand the key features the Future Internet should support in order to meet key challenging requirements. Finally, we compare the requirements with the existing Future Internet research, in order to see how they match to each other.     

Pricing Internet services: proposed improvements

Flat-rate pricing appeals to Internet users and service providers because of its simplicity and predictability. However, congestion is the inevitable consequence of flat-rate pricing because Internet users who pay a fixed access fee have no incentive to limit their network usage. Future applications that require timely delivery of data will require mechanisms for allocating network resources that give consumers choices in services and prices while allowing service providers to recover their costs. We examine the proposed improvements in Internet pricing that are designed to increase its economic efficiency and support the deployment of new applications that require a better quality of service than the Internet currently offers     

网站可信标识架构与查验协议研究

高可信性是下一代互联网的重要特征,主要包括服务提供者可信、信息传输可信和终端用户可信,其中服务提供者的身份可信是构建可信网络的前提。为此,提出一种网站身份可信标识的体系结构,描述基于域名资源记录的网站可信标识查验协议。通过该协议,用户可在各种互联网应用中方便地查询服务提供者的身份信息。实验结果表明,该体系结构与相关查询协议在效率、易用性、可扩展性等方面均可满足实际应用需要,单机查询性能达到15万次／s。     

An Experimental Study of Internet Path Diversity

Several research studies have been devoted to improving the reliability and performance of the Internet by utilizing redundant communication paths between end points. Multihoming, coupled with intelligent route control, and overlay networks are two main streams in this area of research which attempt to leverage redundant connections of the Internet for increased reliability and performance. However, the effectiveness of these approaches depends on the natural diversity of redundant paths between two endhosts in terms of physical links, routing infrastructure, administrative control, and geographical distribution. Even in the case of redundant paths, if traffic between two hosts is not actually routed along completely disjoint paths, congestion or failure of a single shared link or router can adversely affect the end-to-end performance or availability of all paths. This paper presents an experimental study of path diversity on the Internet, focusing on the impact of path diversity on multihomed and overlay networks. We base our analysis on traceroutes and routing table data collected from several vantage points in the Internet including: looking glasses at 10 major Internet service providers (ISPs), RouteViews servers from 20 ISPs, and more than 50 PlanetLab nodes globally distributed across the Internet. Using this data, we quantify the extent of path diversity in multihoming and overlay networks, highlighting the limitations, and also identifying the source of the limitations in these architectures. From the analysis, we learn that both multihoming route control and current overlay networks are not able to ensure path diversity, which makes it very difficult to provide high-availability services even with the use of these systems. We believe that this work provides the insight into building future systems based on understanding path diversity     

TPII: tracking personally identifiable information via user behaviors in HTTP traffic

It is widely common that mobile applications collect non-critical personally identifiable information(PII)from users'devices to the cloud by application service providers(ASPs)in a positive manner to provide precise and recommending services.Meanwhile,Internet service providers(ISPs)or local network providers also have strong requirements to collect PIIs for finer-grained traffic control and security services.However,it is a challenge to locate PIIs accurately in the massive data of network traffic just like looking a needle in a haystack.In this paper,we address this challenge by presenting an efficient and light-weight approach,namely TPII,which can locate and track PIIs from the HTTP layer rebuilt from raw network traffics.This approach only collects three features from HTTP fields as users'behaviors and then establishes a tree-based decision model to dig PIIs efficiently and accurately.Without any priori knowledge,TPII can identify any types of PIIs from any mobile applications,which has a broad vision of applications.We evaluate the proposed approach on a real dataset collected from a campus network with more than 13k users.The experimental results show that the precision and recall of TPII are 91.72%and 94.51%respectively and a parallel implementation of TPII can achieve 213 million records digging and labelling within one hour,reaching near to support 1Gbps wirespeed inspection in practice.Our approach provides network service providers a practical way to collect PIIs for better services.     

A survey on content-centric technologies for the current Internet: CDN and P2P solutions

One of the most striking properties of the Internet is its flexibility to accommodate features it was not conceived for. Among the most significant examples, in this survey we consider the transition of the Internet from a reliable fault-tolerant network for host-to-host communication to a content-centric network, i.e. a network mostly devoted to support efficient generation, sharing and access to content. We survey this research area according to a top-down approach. We present a conceptual framework that encompasses the key building blocks required to support content-centric networking in the Internet. Then we describe in detail the two most important types of content-centric Internet technologies, i.e., Content-Delivery Networks (CDNs) and P2P systems. For each of them, we show how they cover the key building blocks. We then identify the functional components of CDN and P2P content management solutions, and discuss the main solutions proposed in the literature for each of them. We consider different types of content (both real time and non real time), and different networking environments (fixed, mobile, …). Finally, we also discuss the main recent research trends focused on how to design the Future Internet as a native content-centric network.     

区分服务网络中IP多播:问题与解决方案

在下一代因特网中,越来越多的应用将会需要网络提供一定的服务质量以及进行多播传输．因为区分服务体系结构提供了一种可扩展的QoS解决方案,而多播传输则提供了一种节约网络资源的有效方法,二者的集成成为必然趋势．但是,由于区分服务体系结构与多播树结构上的差异,二者的集成存在着一些问题．详细分析了区分服务网络中进行IP多播传输可能出现的问题,并且对近年来提出的各种解决方案进行了分类比较和深入剖析,同时指出了在这一领域中未来的研究方向．     

An efficient relay node selection scheme to improve the performance of P2P-based VoIP applications in Chinese internet

Peer-to-peer (P2P) systems have been widely deployed and used to provide voice-over-IP (VoIP) service in the Internet. However, the current best-effort Internet cannot readily provide the service guarantees that meet the quality standards achieved in the public switched telephone network (PSTN). To address this problem, many studies have demonstrated that exploiting path diversity is a promising approach, such as multi-homing and overlay routing. In this paper, we focus on the overlay scenario and bring forward a previously unexplored approach that exploits the properties of delay space of Internet to select relay node to enhance the performance of P2P-based VoIP applications in Chinese Internet. By conducting intensive Internet measurements, we analyze the properties of delay space of Chinese Internet and show these properties can be readily exploited to select relay node with as small a cost as possible. Exploiting these properties we bring forward an efficient relay node selection scheme to improve the performance of P2P-based VoIP applications in Chinese Internet. Our intensive evaluation by trace-driven simulation shows our scheme is highly efficient and easy to be implemented.     

Identification of adaptive video streams based on traffic correlation

Due to the popularity of Dynamic Adaptive Streaming Over HTTP (DASH), broadband and Internet service providers’ links transmit mainly multimedia content. As the most popular providers encrypt their video services, the attempts to identify their traffic through Deep Packet Inspection (DPI) encounter difficulties. Therefore, encrypted DASH traffic requires new classification methods. In this work, we propose to identify DASH traffic taking into account statistical dependencies among video flows. For this purpose, we employ cluster analysis which can identify groups of traffic flows that show similarity using only the application level information. In our work, we applied three unsupervised clustering algorithms, namely MinMax K-Means, OPTICS and AutoClass, to classify video traces obtained from an emulated environment. The experimental results show that the employed algorithms are able to effectively distinguish video flows generated by different play-out strategies. The classification performance depends on the network conditions and parameters of the learning process.

     

Performance of GSM networks with general packet radio services

Recently, most of the mobile network providers start to introduce general packet radio service (GPRS) in their existing GSM networks. GPRS is the technology that will enable more efficient Internet applications to run on mobile networks even before the installation of 3G systems. However, it is not yet clearly understood, how the new data services will affect the overall network performance. This paper provides a framework for analytical performance evaluation of a single GSM/GPRS cell based on a multidimensional Markov chain model. Important performance measures like new call and handover blocking probabilities, moments of the blocking period distributions, achievable average data rates and resource utilization are determined. Introducing a new connection admission control (CAC) algorithm, different partitioning strategies between GSM and GPRS resources are investigated. Finally, the influence of typical GPRS applications like Internet browsing on traditional GSM services has been studied.     

Explanation-aware service selection: rationale and reputation

A collection of 1 billion¹ publicly available web services can form an internet-scale infrastructure for building diverse applications. For a given application, selection of services and service providers from this collection becomes important and reputation is recognized as a key factor for this purpose. However, current reputation systems are limited in their ability to exchange reputation information between heterogeneous systems. To facilitate meaningful exchange and reuse of reputation information and for the overall determination of reputation, we identify the need to infer and explicate rationale for ratings. We present our knowledge-based approach to inferring and explicating rationale for ratings. We show that this approach facilitates detection of deception and collusion, user preference elicitation, explication of rationale behind user ratings and generation of personalized service recommendations.     

Distributed distance measurement for large-scale networks

There is an increasing trend in the Internet that a set of replicated providers are qualified for a service or resource request from a client. In this case, it is advantageous to select the best provider considering some distance measures, such as hop count or path latency. In this paper, we present a group-based distance measurement service (GDMS), which estimates and disseminates distance information of node-pairs in large-scale wide area networks. GDMS is fully distributed and does not rely on any centralized servers; thus is particularly suitable for the rapidly popularized peer-to-peer applications. The key concept in GDMS is measurement groups (MGroups). Nodes are self-organized into MGroups to form a hierarchical structure. A set of algorithms are proposed to handle network dynamics and optimize the group organization to reduce system costs as well as improve estimation accuracy. Moreover, a novel multicast-based algorithm is used for both intra- and inter-group performance measurements. Performance evaluation over different network topologies shows that GDMS is scalable and provides effective distance information to upper-layer applications at a relatively low cost.     

Federation Lifecycle Management Incorporating Coordination of Bio-inspired Self-management Processes

As it has evolved, the Internet has had to support a broadening range of networking technologies, business models and user interaction modes. Researchers and industry practitioners have realised that this trend necessitates a fundamental rethinking of approaches to network and service management. This has spurred significant research efforts towards developing autonomic network management solutions incorporating distributed self-management processes inspired by biological systems. Whilst significant advances have been made, most solutions focus on management of single network domains and the optimisation of specific management or control processes therein. In this paper we argue that a networking infrastructure providing a myriad of loosely coupled services must inherently support federation of network domains and facilitate coordination of the operation of various management processes for mutual benefit. To this end, we outline a framework for federated management that facilitates the coordination of the behaviour of bio-inspired management processes. Using a case study relating to distribution of IPTV content, we describe how Federal Relationship Managers realising our layered model of management federations can communicate to manage service provision across multiple application/storage/network providers. We outline an illustrative example in which storage providers are dynamically added to a federation to accommodate demand spikes, with appropriate content being migrated to those providers servers under control of a bio-inspired replication process.     

A Cooperation Framework Towards the Internet of Applications

As Internet is changing from a network of data into a network of functionalities, a federated Internet of applications is a natural trending topic, where every application can cooperate with each other smoothly to serve users. Cooperation can be regarded as integrating applications of different providers for users. However, existing integration techniques do not pay enough attention to multiple participants including application providers and end-users. In this study, we advocate a global cooperation framework of Internet of applications for all the participants. Specifically, we propose an intermediary based model to realize the cooperation among applications. With this model, on the one hand, users can be greatly facilitated to cooperatively use applications from various providers to meet their individualized requirements; on the other hand, providers can easily enable their own applications to interact with those from other providers. Thus, the federated Internet of applications is easier to be achieved than using existing solutions. In addition, we implement the model and develop some important techniques, including a) A uniform identity authentication protocol. b) A cooperation execution protocol. c) A multi-vender operated distributed infrustracture. Finally, we show some case studies which demonstrate the effectiveness of this model. In our vision, such a model is the beginning to bring the socialized relationships behind applications into the digital world.