Management of service level agreements for multimedia Internetservice using a utility model

The efficient management of a quality level of Internet service is becoming increasingly important to both customers and service providers. This article describes how service level agreements for multimedia Internet service can be managed and controlled. We first present a literature survey on the problems of SLA management: SLA parameter definition, SLA measurement, and QoS management. We present a utility model to capture the management and control aspects of SLAs for multimedia Internet service. This utility model has been used in microeconomics theory, but here we have applied it to SLA management. This model provides a computationally feasible solution for admission control and quality adaptation for multimedia Internet service and SLA management. It also allows management policies to be flexibly expressed by service providers. Finally, we apply the utility model to the SLA management of VoIP service and describe how to use it for admission control, dynamic quality adaptation, and resource allocation for SLA assurance     

基于动态服务水平协议(SLA)的EPON系统

分析了EPON和动态SLA的特点,在此基础上提出了基于动态SLA的EPON系统.详细说明了在EPON系统中实现动态SLA的方法,其中包括利用资源预留协议(RSVP)进行服务申请和SLA的签订、通过虚拟局域网标识号(VLAN-ID)对SLA进行标识以及采用动态的QoS模型来维护和实现动态SLA.从而增强了由于传统以太网"尽力而为"特性引起的无法对网络资源进行维护和管理的能力,较好地解决了EPON中对各类SLA支持的问题.     

基于线性规划的Internet端到端时延的估计

测量Internet端到端时延特征是研究Internet端到端分组行为的重要内容之一,它能够应用于QoS(Quality of Service),SLA(Service Level Agreement)的管理、拥塞控制算法研究等许多方面.常用的端到端时延测量方法大多依赖于GPS接收机或采用NTP协议来实现收发端时钟的同步,但由于GPS接收机价格较高不可能每台主机都能配备, NTP协议的精度不能满足要求。该文基于线性规划的方法估计收发时钟的频差、相对时钟偏差等参数,以获得端到端时延的估计。作者在几条不同的链路上进行了测试,结果表明该方法能有效消除收发时钟不同步的影响。     

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.     

基于SLA的业务保障在光网络带宽租赁业务中的应用

电信管理网是一个庞大而复杂的网络，如何保障客户业务的质量是电信管理网需要解决的一个重要问题。本以电信管理网的TOM模型为基点，讨论基于SLA的业务保障管理系统的模型和功能实现，并以光传输网络的带宽租赁业务为实例来探讨SLA中的QoS参数的分析与计算，最后提出其系统的外部接口和功能的定义和实现。     

A novel multicast traffic engineering technique in SDN using TLBO algorithm

In recent years, multicast communication is widely used by network providers to deliver multimedia contents. Quality of service (QoS) provisioning is one of the most important issues while transmitting multimedia contents using multicast. Traditional IP multicasting techniques suffer from reliability, scalability and have limitations to provide appropriate QoS for multimedia applications based on service level agreement (SLA). Nowadays, the advent of software defined networking (SDN), enables network providers to manage their networks dynamically and guarantee QoS parameters for customers based on SLA. SDN provides capabilities to monitor network resources and allows to dynamically configure desired multicasting policies. In this paper, we proposed a novel multicasting technique to guarantee QoS for multimedia applications over SDN. To deliver multimedia contents in an efficient manner, our proposed method models multicast routing as a delay constraint least cost (DCLC) problem. As DCLC problem is NP-Complete, we proposed an approximation algorithm using teaching–learning-based optimization to solve this problem. We evaluated our proposed method under different topologies. Experimental results confirmed that our proposed method outperforms IP multicast routing protocol, and it achieves a gain of about 25% for peak signal-to-noise ratio.     

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     

Dynamic random access code assignment for prioritized packet data transmission in WCDMA networks

We propose a measurement-based dynamic random access (RA) code assignment procedure for prioritized packet data transmission in wideband code-division multiple access (WCDMA) networks. This dynamic adaptation process is based on analytical performance results derived for random packet access under Rayleigh fading in WCDMA networks. The performance of the proposed measurement-based RA code assignment procedure with three different adaptation methods is evaluated by using computer simulations. The performance of the proposed scheme is compared with those of a retransmission control-based and static channel allocation-based prioritized packet access scheme. An integrated (physical layer and link layer) delay-throughput performance model is presented for finite population RA WCDMA systems. The proposed dynamic RA code assignment procedure can be used in an adaptive quality of service (QoS) framework for dynamically adjusting the QoS of prioritized RA data traffic in the evolving WCDMA-based differentiated services wireless Internet protocol networks.     

基于分层聚类分析的IPTV业务质量研究与应用

IPTV是基于IP协议的视频业务,与互联网数据业务对网络质量的要求存在很多不同,对网络带宽、QoS性能、可靠性及时延性等方面都要求更高。随着IPTV业务的推广发展和用户对业务质量要求的提高,IPTV业务质量保障变得越来越重要。因此,介绍IPTV网络承载技术,分析IPTV业务质量保障现状及不足,结合SQM系统提出了一种基于分层聚类分析的IPTV业务质量优化方案。     

Evolution of the Internet QoS and support for soft real-time applications

The past few years have witnessed the emergence of many real-time networked applications on the Internet. These types of applications require special support from the underlying network such as reliability, timeliness, and guaranteed delivery, as well as different levels of service quality. Unfortunately, this support is not available within the current "best-effort" Internet architecture. In this paper, we review several mechanisms and frameworks proposed to provide network- and application-level quality of service (QoS) in the next-generation Internet. We first discuss the QoS requirements of many of the above-mentioned real-time applications, and then we categorize them according to the required service levels. We also describe the various building blocks often used in QoS approaches. We briefly present asynchronous transfer mode (ATM) and Internet Protocol precedence. Then, we present and compare two service architectures recently adopted by the Internet Engineering Task Force, called integrated services (IntServ) and differentiated services (DiffServ), for providing per-flow and aggregated-flow service guarantees, respectively. We focus on DiffServ because it is a candidate QoS framework to be used in next-generation Internet along with multiprotocol label switching and traffic engineering. We also examine several operational and research issues that need to be resolved before such frameworks can be put in practice.     

Application type identification of Internet flows based on medium mathematics

Internet application identification is needed by network management in many aspects, such as quality of service(QoS)management, intrusion detection, traffic engineering, accounting, and so on. This article makes an in-depth study of precise identification of Internet applications by using flow characteristics instead of well-known port or application signature match. A novel approach that identifies the application type of an Internet protocol(IP)flow by finding what flow the flow looks the most like based on medium mathematics system(MMS)is proposed. The approach differs from previous ones mainly in two aspects:it has inherent scalability due to its use of the measure of n-dimensional medium truth degree; not only features of a flow, but also the association between the flow and the other flows of the same host as well as the relation among all flows of a host are employed to recognize a flow's application type. For the present, some popular applications are concentrated on, and up to six application types can be identified with better accuracy. The results of experiments conducted on Internet show that the proposed methodology is effective and deserves attention.     

云计算中基于QoS的调配优化算法

研究和设计云计算环境下一种优化的基于QoS约束的调配算法,并验证其正确性。在QoS需求下采用具有服务等级协议(SLA)参数的约束条件,对任务划分优先级,形成优先级队列。SLA服务参数采用二进制权值的方法进行标记,避免了作业分级重叠的情况。在对该任务分配计算资源时,采用资源等级队列的方法,分配合理的工作节点。通过对几种算法的比较实验,验证优化算法运转的鲁棒性和正确性。     

VoIP业务QoS性能及其优化研究

简要介绍了VoIP传输的基本原理,对影响VoIP业务QoS性能的3个主要因素(时延、抖动和丢包)进行分析,提出了利用MPLSdiffserv awareTE(流量工程)集成模型进行端到端QoS性能优化的方法。MPLSdiffserv awareTE能够感知CoS(服务等级),并根据CoS细粒度来预留资源,在每个CoS级别提供MPLS容错机制,能够为VoIP业务提供低丢失、低延迟、低抖动以及确定的带宽服务,很好地满足服务质量要求。     

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.     

“TCP—friendly”的多媒体流分层传输QoS控制策略

针对目前Internet上多媒体流分层传输的QoS控制方案的不足,提出了一种基于接收者的TCP－friendly的QoS控制策略,它利用TCP吞吐量模型和“加强”了的RTCP协议,使接收者能灵活地计算并选择适合其自身能力的媒体传输质量,所设计的区分服务(DiffServ)体系结构下的ERIO机制为多媒体流的不同层次提供不同的转发质量,文中详细讨论了它的实现过程,并给出了计算机模拟测试结果。     

Parallel transport: a new transport layer paradigm for enabling Internet quality of service

The transport layer in the network protocol stack serves as a liaison between the application and the underlying network. Any quality of service provided by the network thus has to be effectively translated by the transport layer protocol in order to be enjoyed by the applications. In this article, we argue for a fundamental rethinking of the transport layer design to facilitate such QoS delivery. We identify the key requirement for a QoS enabling transport layer protocol as the ability to effectively handle multiplicity in terms of user differentiation levels, network resources, and service models. However, TCP, the transport layer protocol predominantly used in the Internet, is unable to support such multiplicity due to its single-state design. We extend TCP to a parallel transport layer protocol called parallel TCP (pTCP) that can tackle the different dimensions of multiplicity, and hence enable varying classes of QoS to applications. We discuss the applicability of pTCP in three specific domains with different levels of network support for QoS, and present simulation results substantiating our arguments.     

Design and implementation of an RSVP-based quality of servicearchitecture for an integrated services Internet

The Internet Engineering Task Force (IETF) is currently in the process of overhauling the architecture of the Internet to meet new challenges and support new applications. One of the most important components of that venture is the enhancement of the Internet service model from a classless best effort service architecture to an integrated services architecture supporting a multitude of classes and types of services. This paper presents the design, implementation, and experiences with a protocol architecture for the integrated services Internet. It is based on the emerging standards for resource reservation in the Internet, namely, the RSVP protocol and the associated service specifications defined by the IETF. Our architecture represents a major functional enhancement to the traditional TCP/IP protocol stack. It is scalable in terms of performance and number of network sessions, and supports a wide variety of network interfaces ranging from legacy LAN interfaces, such as Token Ring and Ethernet, to high-speed ATM interfaces. The paper also describes the implementation of this architecture on the IBM AIX platform and our experiences with the system. We then present a performance analysis of the system which quantifies the overheads imposed by all components of the QoS support, such as traffic policing, traffic shaping, and buffer management     

SLA实现技术及其应用

随着网络服务的内容越来越丰富，用户对服务质量（QoS）的要求也越来越高。为了管理提供QoS保证的电信业务，服务等级协定（SLA）被提出，用来解决用户和服务提供商间有关QoS保证的问题。SLA表示模板、违例处理和指标评价是SLA的3种关键的实现技术。一个典型的SLA管理系统通常包括SLA数据管理、SLA问题管理和SLA管理3个部分。SLA的研究还处于起步阶段。需要进一步规范SLA管理内容。定义通用性和专用性相结合的管理方法，形成统一的工业标准。     

Collected experience from implementing RSVP

Internet quality of service (QoS) is still a highly debated topic for more than fifteen years. Even with the large variety of QoS proposals and the impressive research advances, there is little deployment yet of network layer QoS technology. One specific problem domain is QoS signalling, which has recently attracted increasing attention to bring forward new standardization approaches. In this paper, an extensive study of RSVP is presented, covering protocol design, software design, and performance aspects of the basic version of RSVP and of certain standardized and experimental extensions. This work is based on and presents the experience from implementing RSVP for UNIX systems and the ns-2 simulation environment. The implementation includes a variety of protocol extensions and incorporates several internal improvements. It has been subject to extensive functional and performance evaluations, the results of which are reported here.     

Internet QoS: Pieces of the puzzle

One of the biggest challenges faced when dealing with QoS over the Internet is how to deliver QoS over an unregulated, connectionless network that was designed, deployed, operated, managed, and commercialized without any QoS perspectives. This article gives a concise but comprehensive overview of the Internet QoS puzzle. We aim not only at identifying all the pieces of the puzzle, but also at discovering how to join them together. These include terminology, definitions and standards, architectures, traffic engineering, regulation, accounting, pricing, and marketing. We also explain throughout the article how network providers should envision their service offerings in the context of an SLA and QoS-centric Internet.