On Providing Quality-of-Service Control for Core-Based Multicast Routing

对于嵌入式实时应用程序或多媒体集成分布式控制，在端到端基础上具有QoS保证的高度可预测、及时和可靠的通信服务的需求越来越大。特别是，IETF的RSVP工作组开发了一个资源保留协议（RSVP）协议，为单播/多播数据流提供接收方发起的资源保留设置。RSVP支持接收方发起的固定/共享保留样式，前提是底层路由协议可以提供单播路由/多播树和足够的资源来维持足够的QoS。不幸的是，目前大多数可操作的多播路由协议都没有明确支持QoS（以端到端延迟绑定、端到端目的地间延迟抖动绑定和最小保证带宽的形式）。因此，提出的研究目标是开发和评估QoS路由框架及其相关的准入控制、成员加入/离开过程和信息更新过程，以允许在基于核心的多播路由协议中部署QoS路由功能。所提出的研究是两个协同组成部分的结合：在一个定义良好的分析框架中为所有组件方案建立理论基础和开发，并通过软件系统构建和实验对其进行验证。我们将通过(i)设计有效的准入测试来验证组播组成员是否可以加入组播树，同时不违反对其他树上成员的现有QoS保证；（ii）调查在RSVP中建议的控制负载服务和具有各种保留风格的保证QoS服务的情况下，准入测试所需的最小信息/状态集；（iii）开发（考虑到可扩展性问题）有效的信息更新和状态刷新过程，这些过程可以与存在于大多数利用软状态概念的多播路由协议中的软状态刷新机制轻松集成；（iv）使用Merit Network， Inc.分发的门控组播源代码构建一个实验软件，定义和实现一个丰富的、定义良好的RSVP接口（这可能需要对RSRR （RSVP的路由接口）进行微小的更改），并开发应用程序级库来利用所提议的服务来提供一套具有不同QoS级别的组播服务。欲了解更多信息，请参考项目网页（http://eewww.eng.ohio-state.edu/drcl/grants/qosr98/）。为基于核心的组播路由提供服务质量控制。附件转换：C:\EUDORA\ATTACH\form1239.ps附件转换：C:\EUDORA\ATTACH\form1239.p

There has been an increasing need of highly predictable, timely, and dependable communication services with QoS guarantees on an end-to-end basis either for embedded real-time applications or for multimedia-integrated distributed control. In particular, the RSVP Working Group of the IETF has developed a resource ReSerVation Protocol (RSVP) protocol to provide receiver-initiated setup of resource reservations for unicast/multicast data flows. RSVP supports receiver-initiated, fixed/shared reservation styles under the assumption that a underlying routing protocol is available to provide unicast routes/multicast trees with sufficient resources to maintain adequate QoS. Unfortunately, most of the currently operational multicast routing protocols do not explicitly support QoS (in the form of end-to-end delay bound, end-to-end inter-destination delay jitter bound, and minimum guaranteed bandwidth). The goal of the proposed research is thus to develop and evaluate a QoS routing framework and its associated admission control, member join/leave procedures, and information update procedures, to allow deployment of QoS routing capabilities in core-based multicast routing protocols. The proposed research is a combination of two synergistic components: establishment of theoretical base for, and development of, all the component schemes in a well-defined analytic framework and their validation with software system building and experiments. We will pursue this research by (i) devising effective admission tests to verify whether or not a multicast group member may join the multicast tree, while not violating existing QoS guarantees to other on-tree members; (ii) investigating the minimum set of information/state required for admission tests in the context of the controlled-load service and the guaranteed QoS service with various reservation styles as proposed in RSVP; (iii) developing (with consideration of the scalability issue) effective information update and state refresh procedures that can be read ily integrated with the soft state refresh echanism that exist in most multicast routing protocols that exploit the soft state concept; and (iv) building an experimental software using the GateD multicast source codes distributed by Merit Network, Inc., defining and implementing a rich, well-defined interface with RSVP (which may require minor changes in RSRR, the routing interface for RSVP), and developing application level libraries to exploit the proposed services to provide a suite of multicast services with different levels of QoS. For more information, please refer to the project web page (http://eewww.eng.ohio-state.edu/drcl/grants/qosr98/). On providing quality-of-service control for core-based multicast routing. Attachment Converted: C:\EUDORA\ATTACH\form1239.ps Attachment Converted: C:\EUDORA\ATTACH\form1239.p