COPS-SLS usage for dynamic policy-based QoS management over heterogeneous IP networks

While each IP domain can deploy its own strategy to manage network resources, multimedia traffic needs end-to-end QoS management to obtain an overall service level. The provision of end-to-end QoS over a heterogeneous environment implies the negotiation of a mutually acceptable SLA. This article presents the use of the COPS-SLS protocol as a generic protocol for automatic service-level negotiation and the integration of this protocol in an overall QoS management architecture to manage service levels over multiple domains deploying different QoS technologies.     

A practical architecture for implementing end-to-end QoS in an IPnetwork

All critical elements now exist for implementing a QoS-enabled IP network. It can be built on commercially available platforms and then evolve by adopting emerging standards and technologies. This article describes a practical architecture for end-to-end QoS in an IP environment including incorporation of established, as well as developing, IP and QoS technologies. The article combines the IETF QoS mechanisms with the LAN aspects of QoS and QoS for VoIP-areas usually considered separately. Proposed solutions span across different technologies, e.g., preservation of IP-based classification in MPLS headers, identification of flows encrypted within IPSec during WAN handling, traffic shaping in the access to enable grooming diverse applications and VPNs in the WAN, and so on. VoIP receives special emphasis because of its unique features, such as call setup signaling and call admission control, rarely addressed in traditional IP QoS discussions. An attractive scenario for the IP QoS implementation is to provide a multiservice environment between large enterprise premises over a service provider's core network. A successful end-to-end realization of this service presumes well-defined interworking between the SP's and customers' networks. It will take place on several levels including IP signaling, VoIP setup and CAC, policy interworking, and exchange of billing information. The article recommends to establish SP's presence at the enterprise premises and to implement interworking entities such as the proposed QoS customer server and QoS network server     

Policies for allocating performance impairment budgets among multiple IP providers

An important technical aspect of achieving end-to-end quality of service (QoS) in next generation networks refers to allocation of the total performance impairment budget (delay, jitter, packet loss) among multiple providers. In this article, we first propose a generic policy for allocating per-domain impairment budgets, relying on the set of performance metrics from service request and the rules for their composition on the multi-domain path. The objective is to provide end-to-end QoS through the set of heterogeneous domains, with different QoS models and definitions of service classes. The allocation of impairment budgets among multiple domains is then closely related to mapping of service classes between providers and selection of the most appropriate class for particular service in each domain. Based on the generic policy, we further derive examples of specific policies and evaluate them with respect to fulfillment of QoS objectives, fairness, adaptability and scalability. Evaluation tool implements a policy-based conformance matching scheme, which enforces selection of the domain class that most tightly matches with the required QoS.     

QoS-aware service composition and adaptation in autonomic communication

Advents in network technology and distributed system design have propelled network communication service beyond best effort data delivery. With the rising complexity of network infrastructures and the need for on-demand provisioning operations, a high degree of self-sufficiency and automation is required in the network service infrastructure. Guided by the autonomic communication principle, this paper first presents an autonomic service provisioning framework for establishing quality-of-service (QoS)-assured end-to-end communication paths across administratively independent domains. Through graph abstraction, we show that the domain composition and adaptation problem could be reduced to the classic k-multiconstrained optimal path (MCOP) problem. In analyzing existing k-MCOP solutions, we show their inefficiencies when applied to the service provisioning context and establish a number of new domain composition and adaptation algorithms. These new algorithms are designed for the self-configuration, self-optimization, and self-adaptation of end-to-end network communications and can provide hard QoS guarantees over domains with relative QoS differentiations. Through in-depth experimentations, we compare the performance of our algorithms with classic k-MCOP solutions and demonstrate the effectiveness of our approach.     

Transparent IP radio access for next-generation mobile networks

Advances in network architecture, enhancements in signaling protocols, provisioning of end-to-end QoS, worldwide seamless mobility, and flexible service provision are among the major research challenges toward next-generation wireless networks. The integration and interoperability of all these technologies, along with new truly broadband wireless innovations and intelligent user-oriented services will lead toward the so-called 4G wireless networks. In this article we identify the key issues of an innovative transparent IP radio access system that targets 4G networks.     

A management and control architecture for providing IPdifferentiated services in MPLS-based networks

As the Internet evolves toward the global multiservice network of the future, a key consideration is support for services with guaranteed quality of service. The proposed differentiated services framework is seen as the key technology to achieve this. DiffServ currently concentrates on control/data plane mechanisms to support QoS, but also recognizes the need for management plane aspects through the bandwidth broker. In this article we propose a model and architectural framework for supporting DiffServ-based end-to-end QoS in the Internet, assuming underlying MPLS-based explicit routed paths. The proposed integrated management and control architecture will allow providers to offer both quantitative and qualitative services while optimizing the use of underlying network resources     

QoS routing for MPLS networks employing mobile agents

The implementation of new networking technologies, such as multiprotocol label switching and differentiated services, will introduce powerful features to the near-future Internet backbone, making a significant contribution to the overall end-to-end provision of quality of service. However, to achieve such an improvement these technologies require not only effective support from current routing algorithms, but also enhanced capabilities, which are currently being developed. To contribute to this development, a novel and powerful scheme is introduced in this article that provides a means of supporting QoS routing through the use of mobile software agents. Specifically, we describe the use of mobile agents to efficiently realize multipoint-to-point routing trees by means of the Wave paradigm, while satisfying the QoS requirements of the set of traffic streams involved in the process. Both benefits and important issues to be considered when using mobile agent schemes in QoS routing are further stressed     

在基于GMPLS的无源光网络中支持端到端QoS

文章首先对下一代网络技术的发展趋势以及IETF服务质量（QoS）机制进行了简单介绍,然后对现有无源光网络技术对端到端QoS支持的不足进行了总结,提出了基于通用多协议标签交换（GMPLS）的无源光接入网QoS服务模型。通过在接入网中引入GMPLS通用控制和管理平台,建立了统一的QoS服务模型,实现了对端到端QoS的有效支持。     

A novel monitoring architecture for media services adaptation based on network QoS to perceived QoS mapping

One of the future visions of multimedia networking is the provision of multimedia content at a variety of quality and price levels. Of the many approaches to this issue, one of the most predominant techniques is the concept of Perceived Quality of Service (PQoS), which extends the traditional engineering-based QoS concept to the perceptual satisfaction that the user receives from the reception of multimedia content. In this context, PQoS monitoring is becoming crucial to media service providers (SPs) for providing not only quantified PQoS-based services, but also service assurance based on multimedia content adaptation across heterogeneous networks. This work proposes a novel cross-layer monitoring architecture that utilizes a new Network QoS (NQoS) to PQoS mapping framework at the application level. The resulting QoS monitoring should allow the content delivery system to take sophisticated actions for real time media content adaptation, and aims to provide perceived service performance verification with respect to the QoS guarantees that have been specified in contractual agreements between providers and end-users. A subsequent performance evaluation of the proposed model conducted using a real test-bed environment demonstrates both the accuracy and feasibility of the network level measurements, the NQoS to PQoS mapping and the overall feasibility of the proposed end-to-end monitoring solution. This work is partially funded by European Commission (ENTHRONE EU project IST 507637). See . The authors would like to thank ENTHRONE EU project partners for their inputs and valuable discussions.     

Interdomain routing through QoS-class planes [Quality-of-Service-Based Routing Algorithms for Heterogeneous Networks]

This article presents an approach to delivering qualitative end-to-end quality of service (QoS) guarantees across the multiprovider Internet. We propose that bilateral agreements between a number of autonomous systems (ASs) result in the establishment of QoS-class planes that potentially extend across the global Internet. The deployment of a QoS-enhanced border gateway protocol (BGP) with different QoS-based route selection policies in each of the planes allows a range of interdomain QoS capabilities to coexist on the same network infrastructure. The article presents simulation results showing the benefits of the approach and discusses aspects of the performance of QoS-enhanced BGP     

浅谈无线IP网络中的QoS规范

随着下一代网络的飞速发展,用户之间可以通过多种多样的无线设备相互联络,而这些无线设备则通过一个基于IP的核心网络所提供的无线链路相互连结的。虽然存在如IP协议之类的共同规范,但是要将许多不同的网络融合起来,而这些网络有着各自不同的QoS模型,这无疑将使端到端的QoS保证变得更加复杂。文中讨论了对端到端QoS协议进行标准化的必要性,重点研究了位于服务层的QoS规范,提出了一种通用服务规范(GSS),并对端到端提供QoS保证的服务等级进行了规范。     

Service overlay networks: SLAs, QoS, and bandwidth provisioning

We advocate the notion of service overlay network (SON) as an effective means to address some of the issues, in particular, end-to-end quality of service (QoS), plaguing the current Internet, and to facilitate the creation and deployment of value-added Internet services such as VoIP, Video-on-Demand, and other emerging QoS-sensitive services. The SON purchases bandwidth with certain QoS guarantees from the individual network domains via bilateral service level agreement (SLA) to build a logical end-to-end service delivery infrastructure on top of the existing data transport networks. Via a service contract, users directly pay the SON for using the value-added services provided by the SON. In this paper, we study the bandwidth provisioning problem for a SON which buys bandwidth from the underlying network domains to provide end-to-end value-added QoS sensitive services such as VoIP and Video-on-Demand. A key problem in the SON deployment is the problem of bandwidth provisioning, which is critical to cost recovery in deploying and operating the value-added services over the SON. The paper is devoted to the study of this problem. We formulate the bandwidth provisioning problem mathematically, taking various factors such as SLA, service QoS, traffic demand distributions, and bandwidth costs. Analytical models and approximate solutions are developed for both static and dynamic bandwidth provisioning. Numerical studies are also performed to illustrate the properties of the proposed solutions and demonstrate the effect of traffic demand distributions and bandwidth costs on SON bandwidth provisioning.     

Service level negotiation andcops-sls protocol

The Internet is a set of interconnected domains in which different QoS technologies can be deployed. The dynamic provision of end-to-end QoS over heterogeneousip networks assumes the negotiation of mutually acceptablesla. This paper presents the concept of intra-, inter- and multiple-domain service level negotiation using thecops-sls protocol. The negotiation process gives different parties in the negotiation the ability to agree upon the service level that a data stream can obtain, along with the permissible pricing of the service.     

在Ad Hoc网络中基于信息调度的QoS保证

提出一个以信息调度为基础的分布式的QoS(DQBI)体系结构。该结构可以在移动Ad Hoc网络中为实时传输和尽力而为传输提供QoS保证。DQBI模型改进了整个系统信息端到端的延迟性能,并且通过使用请求允许接入控制和拥塞控制机制来处理网络的拥塞。最后,仿真比较了MQRD结构和DQBI结构,发现DQBI结构可以更好地确保实时流和尽力而为流实现它们期望的服务水平。     

Interdomain quality of service routing: setting the grounds for the way ahead

A common criticism of the current Internet is the fact that it does not offer quality of service (QoS) guarantees across autonomous system boundaries. The Border Gateway Protocol (BGP) is central to solve this problem, since it enables AS to distribute reachability information. However, BGP is agnostic of any performance or QoS metrics. For this reason, the debate about the requirements for the future interdomain routing architecture and about whether these requirements are best met by an approach of introducing changes into BGP or by replacing BGP is still open. This article provides an insight into the interdomain QoS routing problem. First, the main drawbacks of current interdomain routing with regard to the provision of QoS are identified. Second, a survey of the most relevant interdomain QoS routing approaches are described and discussed. We also give a broad perspective on challenges surrounding the issue of whether to extend or replace BGP to support QoS, with particular emphasis on the technical challenges. However, we also point out some nontechnical unsolved challenges that, in our perspective, are still almost certainly the biggest barrier to the development of interdomain QoS routing.     

A scalable framework for in IP-oriented terrestrial-GEO satellite networks

The exponential growth of the Internet, the heterogeneity of networks, and the need for QoS maintenance have urged researchers to develop ideas for managing network scalability and end-to-end QoS assurance. In this article, an IP IntServ architecture in the satellite access network is combined with a scalable IP DiffServ-like architecture in the terrestrial core network. The proposed architecture aims at guaranteeing fine-grained bandwidth control in the satellite access network and stateless scalability in the core network, by exploiting per-aggregate traffic flow control, typical of the aggregate RSVP protocol, and stateless service assurance, typical of the SCORE approach.     

End-to-end QoS specification issues in the converged all-IP wired and wireless environment

The emerging next-generation networking environment presents an IP-based core interconnecting many wireless radio access networks, providing ubiquitous access to end users through a vast variety of wireless devices. Although the IP protocol is the common denominator, the new environment brings together many different interconnecting domains, each following different QoS models, complicating the overall end-to-end QoS process. This article discusses the need to standardize an end-to-end QoS protocol. It does not, however, focus on the signaling mechanism, since there is currently a relevant ongoing activity in IETF. Instead, it concentrates on the formulation of the QoS information describing the QoS requirements of the session to be established. It presents the generic service specification framework that not only enables the QoS requirements of a specific session to be captured (like a generic QoS template), but also the QoS classes of each IP domain can be described according to it. Through the systematic specification of a domain's QoS classes, an intelligent automatic mapping algorithm can be applied during an end-to-end QoS request, in order to select the most appropriate service class in each domain, as well as to extract the required traffic-related parameters to perform traffic control operations, such as admission control, policing, and scheduling.     

A flexible and distributed architecture for adaptive end-to-end QoS provisioning in next-generation networks

A novel distributed end-to-end quality-of-service (QoS) provisioning architecture based on the concept of decoupling the end-to-end QoS provisioning from the service provisioning at routers in the differentiated service (DiffServ) network is proposed. The main objective of this architecture is to enhance the QoS granularity and flexibility offered in the DiffServ network model and improve both the network resource utilization and user benefits. The proposed architecture consists of a new endpoint admission control referred to as explicit endpoint admission control at the user side, the service vector which allows a data flow to choose different services at different routers along its data path, and a packet marking architecture and algorithm at the router side. The achievable performance of the proposed approach is studied, and the corresponding results demonstrate that the proposed mechanism can have better service differentiation capability and lower request dropping probability than the integrated service over DiffServ schemes. Furthermore, it is shown that it preserves a friendly networking environment for conventional transmission control protocol flows and maintains the simplicity feature of the DiffServ network model.     

支持IPv6／RSVP的网络中基于数字视频的教育服务

为了保证基于数字视频的教育服务的网络的服务质量,更好地提升Internet的网络性能,使综合数据的传输更加流畅,将IPv6相对于IPv4的优势和RSVP对的QoS支持两方面结合起来,提出了支持IPv6／RSVP的网络中基于数字视频的教育服务的基本设计思想、系统总体框架结构与技术实现,并给出了视频教育服务体系结构、通信协议栈和资源预留的实现方式。该方法在拟定的实验环境下能实现预期目标,并被证明了有为基于教育服务的视频提供端对端服务质量的可能性。     

QoS issues in the converged 3G wireless and wired networks

The Internet evolution delineated through the last years has urged the wireless network community to support the deployment of IP multimedia services with guaranteed quality of service (QoS) in 3G wireless networks. This article copes with the interoperability between 3G wireless networks and wired next-generation IP networks, for the provision of services with an a priori known quality level over both environments. More specifically, the UMTS architecture as well as a prototypical implementation of the next-generation Internet based on DiffServ are considered. The article focuses on the mapping among the traffic classes of the two networks at the point where the networks converge, and discusses the requirements and possible solutions for their proper interworking at the signaling and user levels. Simulations prove that proper mapping among the traffic classes of each world is necessary in order to achieve the desired end-to-end traffic characteristics.