'QOS Enhancement with Partial State'

在设计用于在网络内提供服务保证的机制方面已经做了大量工作。这些方案可以大致分为两类，需要为每个流维护状态的方案和不需要为网络中的每个流维护状态的方案。集成服务体系结构、区分服务体系结构和区分服务体系结构就是这些方法的主要示例。这两种方法都有各自的优势和支持者。该建议旨在研究介于两个极端之间的方法，在这种方法中，网络交换机可能能够维持固定数量的流的状态(可能少于其服务的流数量)。这项提案着眼于有限数量的国家可以提供的服务。该提案计划继续研究为有限数量的国家提供QOS的新方法的大方向。我们的初步工作确定了以下指导原则：*所提供的服务需要是灵活的，即应该能够在任何数量的状态下工作(相对于流的数量)。*提供的服务需要是可扩展的，即增加状态数量应该提高QOS。*提供的服务需要是累加的，即随着更多的网络组件使用它，QOS应该得到改善。提案计划研究能够提供以下QOS的机制：*识别和限制无响应流的资源消耗。*提供公平的带宽共享。*为不同的流提供带宽分配。作为第一步，我们建议在路由器上使用采样和缓存以及队列和缓冲区管理技术来提高服务质量。该机制使用缓存来处理有限数量的状态，并使用采样来选择要为其维护单个状态的流。我们的初步结果表明，采样和缓存可以有效地用于遏制非响应流和公平共享带宽。该方案计划研究在IntServ和DiffServ等当前定义的体系结构中采用部分状态的有效性和可行性。该提案还计划研究是否可以使用部分状态来提供延迟和抖动服务。除了研究机制外，该提案还计划对部分状态的有用性进行跟踪驱动和统计分析。可用的网络跟踪将用于研究状态对网元上要完成的工作量的影响以及此类机制对QOS的影响。我们还计划使用易于理解的网络流量模型来分析部分状态，看看能否对部分状态的影响得出定性结论。

Considerable work has been done in devising mechanisms for providing service guarantees within a network. These schemes can be broadly classified into two categories, schemes that require maintaining state for each flow and schemes that do not require maintaining state for each flow withing the network. Integrated services architecture and differentiated services architecture and differentiated services architecture are prime examples of such approaches. Both the approaches have their advantages and proponents. This proposal aims to investigate approaches that fall in between two extremes, where a network switch may be able to maintain state for a fixed number of flows (possibly less than the number of flows it serves). This proposal looks at the services that can be provided by a limited amount of state. The proposal plans to pursue the general direction of investigating new approaches for providing QOS with a limited amount of state. Our initial work has identified the following guiding principles:*The provided service needs to be flexible i.e., should be able to work with any amount of state (relative to the number of flows). *The provided service needs to be scalable i.e., increased amount of state should improve QOS.*The provided service needs to be additive i.e., as more network components employ it, QOS should be improved.The proposal plans to investigate mechanisms that can provide the following QOS:*Identify and limit the resource consumptions of non-responsive flows.*Provide fair sharing of bandwidth.*Provide bandwidth allocations to different flows. As a first step, we propose to employ Sampling and Caching in addition to queue and buffer management techniques at a router to enhance the QoS. The proposed mechanism uses caching to deal with the limited amount of state and uses sampling to select flows for which individual state is maintained. Our preliminary results show that sampling and caching can be effectively used for containing non-responsive flows and fair sharing of bandwidth. The proposal plancs to study the effectiveness and feasibility of employing partial state in currently defined architectures such as IntServ and DiffServ. The proposal also plans to study if partial state can be used to provide delay and jitter service. Besides studying mechanisms, the proposal also plans to do both trace-driven and statistical analysis of usefulness of partial state. Available network traces will be used to study the impact of state on the amount of work to be done at a network element and the QOS impact of such mechanisms. We also plan to analyze partial state with well understood models of network traffic to see if we can make qualitative conclusions about the impact of partial state.