Bandwidth Aggregation-Aware Dynamic QoS Negotiation for Real-Time Video Streaming in Next-Generation Wireless Networks

In next generation wireless networks, Internet service providers (ISPs) are expected to offer services through several wireless technologies (e.g., WLAN, 3G, WiFi, and WiMAX). Thus, mobile computers equipped with multiple interfaces will be able to maintain simultaneous connections with different networks and increase their data communication rates by aggregating the bandwidth available at these networks. To guarantee quality-of-service (QoS) for these applications, this paper proposes a dynamic QoS negotiation scheme that allows users to dynamically negotiate the service levels required for their traffic and to reach them through one or more wireless interfaces. Such bandwidth aggregation (BAG) scheme implies transmission of data belonging to a single application via multiple paths with different characteristics, which may result in an out-of-order delivery of data packets to the receiver and introduce additional delays for packets reordering. The proposed QoS negotiation system aims to ensure the continuity of QoS perceived by mobile users while they are on the move between different access points, and also, a fair use of the network resources. The performance of the proposed dynamic QoS negotiation system is investigated and compared against other schemes. The obtained results demonstrate the outstanding performance of the proposed scheme as it enhances the scalability of the system and minimizes the reordering delay and the associated packet loss rate.     

Peer-to-peer based multimedia distribution service

Recently, there are many research interests in providing efficient and scalable multimedia distribution service. However, stringent quality-of-service (QoS) requirements for media distribution, as well as dynamically changing and heterogeneous network capacity in today's best effort Internet, bring many challenges. In this paper, we introduce a novel framework for multimedia distribution service based on peer-to-peer (P2P) networks. A topology-aware overlay is proposed in which hosts self-organize into groups. End hosts within the same group have similar network conditions and can easily collaborate with each other to achieve QoS awareness. In order to improve media delivery quality and provide high service availability, we further propose two distributed heuristic replication strategies, intergroup replication and intragroup replication, based on this topology-aware overlay. Specifically, intergroup replication is aimed to improve the efficiency of media content delivery between the group where a request is issued and the group where the content is stored. Also, intragroup replication is targeted at improving the availability of the content. Extensive simulation results show that the latency in our proposed architecture is 20% less than that of the FreeNet and 50% less than that of the randomly replication system. Simulation results also show that the video quality in our system is much better than that in the other two systems. Our P2P-based approach is also distributed, scalable, cost effective, and aware of the performance.     

主动网技术的发展趋势

主动网(ActiveNetwork)是一种新型的网络体系结构,与传统网络体系结构相比,其显著特点是,主动网增加了路由器或交换机等网络结点的计算能力,从而为用户提供了方便、灵活的网络服务定制能力。随着网络应用的日益增长和多样化,用户越来越要求网络能够提供灵活的、可扩展的网络服务。该文对主动网体系结构进行了深入的研究,结合当前国际上对主动网技术的研究新动向,重点讨论了主动网的服务定制能力,并提出了今后的发展方向。     

基于语义覆盖网络的信息组织与服务体系框架

针对广域网络环境下面向用户需求的信息服务要求,本文设计了一种基于语义覆盖网络的信息组织与服务体系框架。该框架充分考虑用户的信息需求与信息体系,提供了一种趋于扁平化的信息共享与服务环境。该框架通过自底向上和自顶向下相结合的信息组织模式,在信息资源中心完成基于语义的信息整合与组织的基础上采用基于语义相似度聚类的语义覆盖网络,提供基于语义的信息资源发布、发现与定位的能力。     

A Query Routing Approach Based on Users’ Satisfaction for Resource Discovery in Service-Oriented Networks

Service oriented networks are distributed computing infrastructures that provide widely distributed resources. These networks are dynamic and their size and complexity continue to increase and allow to users a ubiquitous access to available resources and services. Therefore, efficient query routing approaches in large and highly distributed service oriented networks are required and need to be adaptive in order to cope with a dynamically changing environment. In this paper, a query routing approach based on mobile agents and random walks with a reinforcement learning technique is presented. By enhancing random walks with a reinforcement learning mechanism centered on users’ satisfaction, this approach allows dynamic and self-adaptive location of required resources. Peers incorporate knowledge from past and present queries which will be used during next searches by mobile agents to select their next hops. This approach is analyzed through two query routing techniques using the network simulator ns2.     

基于下一代Internet的服务管理研究

Internet is best effort network, on the whole, it doesn't provide any quality of service assurance for services. Especially,all kinds of stream media need more network performance and quality of service. Currently, because of existing many heterogeneous networks, such as telecommunication network, IP data network , mobile network and so on ,in order to break off this heterogeneous network isolated complexion ,research and developmentnext generation network must be carried out,only by this way,can these isolated heterogeneous network be merged into an all IP network. This network will provide enormous services for service users,how to manage these services effectively is a topic proposed by next generation internet. [1] gave research status for service management and advance,this paper researches service management requirement for next generation Internet and workflow etc,and based on these technique,a service management architecture model is proposed. It consists of service access layer, service deployment layer, service providing layer, service mapping layer, policy control layer and network element managing layer. These layers coordinate to implement service management.     

On the analysis of overlay failure detection and recovery

Application-layer overlay networks have been proposed as an alternative method to overcome IP-layer path anomalies and provide users with improved routing services. Running at the application layer, overlay networks usually rely on probing mechanisms for IP-path performance monitoring and failure detection. Their service performance is jointly determined by their topology, parameters of probing mechanism and failure restoration methods. In this paper, we first define metrics to evaluate the performance of overlay networks in terms of failure detection and recovery, network stability and overhead. Second, we model the overlay-based failure detection and recovery process. Through extensive simulations, we investigate how different IP-layer path failure characteristics and overlay topologies, detection and restoration parameters affect service performance of overlay networks. In particular, we examine the tradeoffs among different overlay performance metrics and the optimal performance conditions. Our study helps to understand overlay-based failure recovery and provides practical guidance to overlay network designers and administrators.     

An Adaptive Policy-Based Framework for Network Services Management

This paper presents a framework for specifying policies for the management of network services. Although policy-based management has been the subject of considerable research, proposed solutions are often restricted to condition-action rules, where conditions are matched against incoming traffic flows. This results in static policy configurations where manual intervention is required to cater for configuration changes and to enable policy deployment. The framework presented in this paper supports automated policy deployment and flexible event triggers to permit dynamic policy configuration. While current research focuses mostly on rules for low-level device configuration, significant challenges remain to be addressed in order to:a) provide policy specification and adaptation across different abstraction layers; and, b) provide tools and services for the engineering of policy-driven systems. In particular, this paper focuses on solutions for dynamic adaptation of policies in response to changes within the managed environment. Policy adaptation includes both dynamically changing policy parameters and reconfiguring the policy objects. Access control for network services is also discussed.     

Access and service convergence over the mobile internet – A survey

Next generation heterogeneous wireless networks are expected to interwork with Internet Protocol (IP)-based infrastructures. Conventional network services operate like silos in that a specific set of services are offered over a specific type of access network. It is desirable for users to be able to roam between fixed and mobile networks that employ different access technologies. Therefore, mobility management with quality of service (QoS) support is of particular importance and one of the driving forces of convergence. Since service providers often provide more than one service to their subscribers, it is important to facilitate convergence of network charging architecture through a common charging framework. One of the main issues of IP-based convergence is security and privacy. This requires coordination of different security policies in diverse networks that have different security levels and capabilities. The business case for migration to an IP-based platform motivates operators to deliver more powerful services for customers as well as a better user experience. This paper provides an overview of converged mobile Internet architectures and their implications on QoS, charging/billing and security, as well as emerging business models for telecommunication services.     

Resource management policies in GPRS systems

In this paper we consider the problem of resource management in GSM/GPRS cellular networks offering not only mobile telephony services, but also data services for the wireless access to the Internet. In particular, we investigate channel allocation policies that can provide a good tradeoff between the QoS guaranteed to voice and data services end users, considering three different alternatives, and developing analytical techniques for the assessment of their relative merits. The first channel allocation policy, voice priority, gives priority to voice in the access to radio channels; we show that this policy cannot provide acceptable performance to data services, since when all the channels are busy with voice connections, data services perceive long intervals of service interruption. The second channel allocation policy is called R-reservation; it statically reserves a fixed number of channels to data services, thus drastically improving their performance, but subtracting resources from voice users, even when these are not needed for data, thus inducing an unnecessary performance degradation for voice services. The third channel allocation policy is called dynamic reservation; as the name implies, it dynamically allocates channels to data when necessary, using the information about the queue length of GPRS data units within the base station. A threshold on the queue length is used in order to decide when channels must be allocated to data. Numerical results show that the dynamic reservation channel allocation policy can provide effective performance tradeoffs for data and voice services, with the additional advantage of being easily managed through the setting of the threshold value.     

主动网络的研究进展与展望

主动网络是一种新型的网络体系结构,与传统网络体系结构相比,主动网络增加了路由器或交换机等网络中间节点的计算能力和可编程能力,从而为用户提供了方便、灵活的网络服务定制能力.随着网络应用的日益增长和多样化,用户要求网络能够提供灵活、可扩展的网络服务.该文全面总结了主动网络的研究现状,结合主动网络技术的研究新动向和主动网络的应用,给出了今后的研究方向.     

A user-centric approach to service creation and delivery over next generation networks

Next Generation Networks (NGN) provide Telecommunications operators with the possibility to share their resources and infrastructure, facilitate the interoperability with other networks, and simplify and unify the management, operation and maintenance of service offerings, thus enabling the fast and cost-effective creation of new personal, broadband ubiquitous services. Unfortunately, service creation over NGN is far from the success of service creation in the Web, especially when it comes to Web 2.0. This paper presents a novel approach to service creation and delivery, with a platform that opens to non-technically skilled users the possibility to create, manage and share their own convergent (NGN-based and Web-based) services. To this end, the business approach to user-generated services is analyzed and the technological bases supporting the proposal are explained.     

Scalable services via egress admission control

Allocating resources for multimedia traffic flows with real-time performance requirements is an important challenge for future packet networks. However, in large-scale networks, individually managing each traffic flow on each of its traversed routers has fundamental scalability limitations, in both the control plane's requirements for signaling, state management, and admission control, and the data plane's requirements for per-flow scheduling mechanisms. In this paper, we develop a scalable architecture and algorithm for quality-of-service management termed egress admission control. In our approach, resource management and admission control are performed only at egress routers, without any coordination among backbone nodes or per-flow management. Our key technique is to develop a framework for admission control under a general “black box” model, which allows for cross traffic that cannot be directly measured, and scheduling policies that may be ill-described across many network nodes. By monitoring and controlling egress routers' class-based arrival and service envelopes, we show how network services can be provisioned via scalable control at the network edge. We illustrate the performance of our approach with a set of simulation experiments using highly bursty traffic flows and find that despite our use of distributed admission control, our approach is able to accurately control the system's admissible region under a wide range of conditions     

Inter-domain policy violations in multi-hop overlay routes: Analysis and mitigation

The Internet is a complex structure arising from the interconnection of numerous autonomous systems (AS), each exercising its own administrative policies to reflect the commercial agreements behind the interconnection. However, routing in service overlay networks is quite capable of violating these policies to its advantage. To prevent these violations, we see an impending drive in the current Internet to detect and filter overlay traffic. In this paper, we first present results from a case study overlay network, constructed on top of PlanetLab, that helps us gain insights into the frequency and characteristics of the different inter-domain policy violations. Further, we investigate the impact of two types of overlay traffic filtering that aim to prevent these routing policy violations: blind filtering and policy-aware filtering. We show that such filtering can be detrimental to the performance of overlay routing. We next consider two approaches that allow the overlay network to realize the full advantage of overlay routing in this context. In the first approach, overlay nodes are added so that good overlay paths do not represent inter-domain policy violations. In the second approach, the overlay acquires permits from certain ASes that allow certain policy violations to occur. We develop a single cost-sharing framework that allows the incorporation of both approaches into a single strategy. We formulate and solve an optimization problem that aims to determine how the overlay network should allocate a given budget between paying for additional overlay nodes and paying for permits (transit and exit) to ASes. We illustrate the use of this approach on our case study overlay network and evaluate its performance under varying network characteristics.     

Adaptive middleware supporting scalable performance for high-end network services

Network service-based computation is a promising paradigm for both scientific and engineering, and enterprise computing. The network service allows users to focus on their application and obtain services when needed, simply by invoking the service across the network. In this paper, we show that an adaptive, general-purpose run-time infrastructure in support of effective resource management can be built for a wide range of high-end network services running in a single-site cluster and in a Grid. The primary components of the run-time infrastructure are: (1) dynamic performance prediction; (2) adaptive intra-site resource management; and (3) adaptive inter-site resource management. The novel aspect of our approach is that the run-time system is able to dynamically select the most appropriate performance predictor or resource management strategy over time. This capability not only improves the performance, but also makes the infrastructure reusable across different high-end services. To evaluate the effectiveness and applicability of our approach, we have transformed two different classes of high-end applications—data parallel and distributed applications—into network services using the infrastructure. The experimental results show that the network services running on the infrastructure significantly reduce the overall service times under dynamically varying circumstances.     

Virtual Strategy QoS routing in satellite networks

Satellite network users want to unify different satellites to enhance the quality-of-service (QoS) stability of the satellite networks and select feasible paths through different networks to feed different applications. Unfortunately, the state of affairs is that different applications need to use several different application programming interfaces and to design different protocols on how and when to use a specific network. This is troublesome and error-prone as the application programming interfaces vary a lot. In this paper, we design a Virtual Strategy in satellite network based on which a QoS routing service scheme is then proposed. We analyze why applications should use and benefit from Virtual Strategy. This Virtual Strategy is a middleware solution that enables seamless usage of services from different satellite network parts. And then, the supporting QoS routing solution enables the committed QoS services over Virtual Strategy. Finally, we provide a comparison between the previous satellite networks and our work. The simulation results show that our Virtual Strategy QoS routing scheme demonstrates dominated performances under complex architecture.     

基于模糊逻辑的资源感知P2P重叠网及其应用研究

P2P重叠网以其系统高效性和有效性被广泛应用于分布式网络管理系统中。但是,传统P2P重叠网络的设计往往只关注其P2P特性,忽略了重叠网自身的管理问题;另外,P2P网络强调的是参与者的平等性,忽略了各参与节点自身性能的差异,从而极大影响了系统的整体性能。本文提出一种基于模糊逻辑的资源感知P2P重叠网,系统中的每个参与节点负责管理一部分网元设备,并充分考虑各节点所管理资源的可用性及其所处环境的时变特性,同时利用基于策略的网络管理方式,构建了一种动态和自主的P2P重叠网网络管理系统。仿真结果证明了该方案在网络管理中的可行性和有效性。     

Network-aware service placement and selection algorithms on large-scale overlay networks

Currently many service providers offer their services on a private and proprietary hard- and software infrastructure. These infrastructures often share many similarities. Hence we believe a generic service management architecture, that allows service providers to offer a large array of different services on a single infrastructure or multiple providers to offer their services cooperatively, would provide many advantages over current silo-based approaches. Additionally, by allowing the distributed service management components to cooperate in a peer-to-peer overlay network, scalability and resilience of the system could be greatly improved.In this paper we propose an optimal algorithm, based on an integer linear programming (ILP) formulation, and several heuristics to support such a generic overlay-based service management architecture. More specifically, we propose algorithms for dynamically allocating server and network resources to a set of services and selecting a suitable service instance for each client. Service instances are placed on a set of servers, taking into account server resource constraints (e.g. CPU and memory). Unlike existing algorithms for this problem, those proposed in this paper also support service level agreements (SLAs), which take the form of Quality of Service demands such as transmission latency constraints and bandwidth requirements. The optimisation goal is to maximise the percentage of satisfied demand (answered requests) and minimise the total number of required overlay servers, while satisfying the SLAs and resource constraints. Additionally, we propose an extension that allows the algorithms to find overlay routing paths to improve the transmission latency for latency-sensitive services.Extensive simulations were performed to evaluate the performance and scalability of the heuristics. They showed that in many cases the heuristics perform close to optimal and they scale well in terms of network size.     

ANEMA: Autonomic network management architecture to support self-configuration and self-optimization in IP networks

The increasing scale, technology advances and services of modern networks have dramatically complicated their management such that in the near future it will be almost impossible for human administrators to monitor them. To control this complexity, IBM has introduced a promising approach aiming to create self-managed systems. This approach, called Autonomic Computing, aims to design computing equipment able to self-adapt its configuration and to self-optimize its performance depending on its situation in order to fulfill high-level objectives defined by the human operator.In this paper, we present our autonomic network management architecture (ANEMA) that implements several policy forms to achieve autonomic behaviors in the network equipments. In ANEMA, the high-level objectives of the human administrators and the users are captured and expressed in terms of ‘Utility Function’ policies. The ‘Goal’ policies describe the high-level management directives needed to guide the network to achieve the previous utility functions. Finally, the ‘behavioral’ policies describe the behaviors that should be followed by network equipments to react to changes in their context and to achieve the given ‘Goal’ policies.In order to highlight the benefits of ANEMA architecture and the continuum of policies to introduce autonomic management in a multiservice IP network, a testbed has been implemented and several scenarios have been executed.     

Objective Risk Evaluation for Automated Security Management

Network security depends on a number of factors. And a common characteristic of these factors is that they are dynamic in nature. Such factors include new vulnerabilities and threats, the network policy structure and traffic. These factors can be divided into two broad categories. Network risk and service risk. As the name implies, the former one corresponds to risk associated with the network policy whereas the later one depends on the services and software running on the system. Therefore, evaluating security from both the service and policy perspective can allow the management system to make decisions regarding how a system should be changed to enhance security as par the management objective. Such decision making includes choosing between alternative security architectures, designing security countermeasures, and to systematically modify security configurations to improve security. As there may be real time changes to the network threat, this evaluation must be done dynamically to handle such changes. In this paper, we provide a security metric framework that quantifies objectively the most significant security risk factors, which include existing vulnerabilities, historical trend of vulnerabilities of the remotely accessible services, prediction of potential vulnerabilities for these services and their estimated severity, unused address space and finally propagation of an attack within the network. These factors cover both the service aspect and the network aspect of risk toward a system. We have implemented this framework as a user-friendly tool called Risk based prOactive seCurity cOnfiguration maNAger (ROCONA) and showed how this tool simplifies security configuration management of services and policies in a system using risk measurement and mitigation. We also combine all the components into one single metric and present validation experiments using real-life vulnerability data from National Vulnerability Database (NVD) and show comparison with two existing risk measurement tools.