ITR: Collaborative Research:Scalable Quality-of-Service Control for the Next Generation Internet: Fundamental Challenges and Effective Solutions

今天的互联网之所以取得巨大成功，要归功于25年前简单的、“沙漏”式的IP网络协议架构。近年来，随着网络技术的快速发展和丰富的多媒体内容的爆炸性增长，网络社区发现自己处于一个重要的十字路口：下一代互联网体系结构应该是什么，以控制网络资源并提供新兴多媒体应用所需的服务质量(Qos)？有多种可能的方法来提供服务质量保证。为下一代互联网选择服务质量解决方案将对互联网本身的发展及其实现产生重大影响。要做出正确的选择，需要对服务质量控制的可扩展性以及这些控制对服务质量保障有效性的影响有一个基本的了解。拟议的研究的目标是全面、定量地了解提供可扩展的服务质量保证的各种方法所涉及的基本权衡。为此，研究人员将开发连贯的理论来系统地解决服务质量控制中的可扩展性问题。该研究计划大致分为四个领域：保证流的聚合网络演算：为了彻底了解网络系统在提供服务质量性能保证方面的精细时间尺度(例如，分组级别)行为，研究人员将开发聚合网络演算，以研究聚合服务质量控制机制对数据平面操作的性能和复杂性的影响。这一理论是为保证流开发的-流要求网络在其整个生命周期内在每个流或聚合级别提交一定量的资源(例如，带宽和缓冲区)，而不考虑网络拥塞状态。聚合网络演算将提供一个数学框架来量化聚合服务质量控制对服务质量配置中基本权衡的影响，还将为可扩展数据平面服务质量控制机制的设计提供见解。响应流的端到端服务质量控制：研究人员将开发流体模型来研究聚合服务质量控制机制对响应流端到端性能的影响。响应流通过调整其传输速率来响应网络拥塞的迹象，例如丢失。这些模型将使我们能够更好地理解响应流的行为，如结合不同的聚合Qos机制的TCP，并为响应流设计端到端的Qos服务。研究人员将开发用于捕获网络的慢时间尺度、系统范围行为的服务质量控制规律，以及解决服务质量聚合控制下控制平面操作的性能和复杂性的聚合规则。这些服务质量控制规则和聚合规则将引导我们设计用于可扩展控制平面操作的分布式和集中式算法。可扩展服务质量机制和服务体系结构作为发展这些理论的一个组成部分，研究人员还将设计有效且可扩展的服务质量机制，以及用于量化和评估各种服务质量解决方案的工具和技术。基于这些努力的结果，研究人员将研究如何组合各种服务质量解决方案来构建有意义的端到端服务。研究将结合形式建模/分析、实验/实现和评估。通过研究获得的理解和见解将导致建立理论、设计原则和指导方针，为未来的互联网构建可扩展的Qos控制。反过来，随着下一代互联网的形成，这将使人们能够做出理性和明智的选择。

Today's Internet owes its great success to the simple, "hour-glass" IP network protocol architecture laidout twenty-five years ago. With rapid advances in networking technologies and explosive growth of richmultimedia content in recent years, the networking community finds itself at an important crossroads: whatshould be the next generation Internet architecture for controlling network resources and provide the qualityof service (QoS) needed by emerging multimedia applications? There is a multidimensional spectrum ofpossible approaches to providing QoS guarantees. The choice of a QoS solution for the next generationInternet will have a substantial impact on both the evolution of the Internet itself, and on what it enables.Making the "right" choices requires the development of a fundamental understanding of the scalability ofQoS controls and the impact of these controls on the efficacy of QoS provisioning.The goal of the proposed research is to develop a comprehensive, quantitative understanding of thefundamental trade-offs involved in various approaches toward providing scalable QoS guarantees. To thisend, the researchers will develop coherent theories to systematically address the issue of scalability in QoS controls. The research program divides broadly into four areas:Aggregate network calculus for guaranteed flows: To gain a thorough understanding of the fine time-scale(e.g., packet-level) behavior of a network system in providing QoS performance guarantees, the researcherswill develop an aggregate network calculus to study the impact of aggregate QoS control mechanismson the performance and complexity of data plane operations. This theory is developed for guaranteedflows - flows which require the network to commit, either at a per-flow or an aggregate level, acertain amount of resources (e.g., bandwidth and buffer) throughout their life time, regardless of thenetwork congestion status. The aggregate network calculus will provide a mathematical frameworkto quantify the impact of aggregate QoS controls on the fundamental trade-offs in QoS provisioning.It will also yield insights into the design of scalable data plane QoS control mechanisms.End-to-end QoS controls for responsive flows: The researchers will develop fluid models to study the impact of aggregate QoS control mechanisms on the end-to-end performance of responsive flows. A responsiveflow responds to signs of network congestion, such as loss, by adapting its transmission rate. Thesemodels will enable us to develop a better understanding of the behavior of responsive flows such asTCP coupled with different aggregate QoS mechanisms and to design end-to-end QoS services forresponsive flows.QoS control laws and control plane aggregation rules. The researchers will develop QoS control laws for capturing the slow time-scale, system-wide behavior of a network and aggregation rules that address the performance and complexity of control plane operations under aggregate QoS controls. These QoS controllaws and aggregation rules will lead us to the design of distributed and centralized algorithms forscalable control plane operations.Scalable QoS mechanisms and service architectures as an integral part in developing these theories, the researchers will also design effective and scalable QoS mechanisms, and tools and techniques for quantifying and evaluating the trade-offs of various QoS solutions. Based on the results from these efforts, the researchers will study how various QoS solutions can be combined to construct meaningful end-to-end services.The research will blend formal modeling/analysis, experimentation/implementation, and evaluation. Theunderstanding and insights gained as a result of the research will lead to the establishment of the theory,design principles, and guidelines for building scalable QoS controls for the future Internet. This, in turn,will allow reasoned and informed choices to be made as the next generation Internet takes shape.