ITR: Stateless Quality of Service Routing in IP Networks

该项目旨在开发和实验评估IP网络中无状态服务质量路由（SQUARN）的框架。最近的一些研究已经认识到对QoS路由解决方案的需求，并导致了在IP路由协议中引入QoS扩展的一些持续努力。到目前为止，QoS路由的工作都是在底层网络架构是基于保留的假设下进行的。在这样的体系结构中，路由器必须维护每个流的状态信息，终端系统必须使用显式的信令消息来传递它们的QoS要求。这种显式保留模型虽然从网络控制的角度来看很有吸引力，但存在可伸缩性问题。提出的SQUARN模型旨在提供无状态QoS路由解决方案，这些解决方案可以集成到无预约QoS框架（例如DiffServ）中。SQUARN依赖于动态数据包转发机制，该机制新颖地利用了IP数据包报头中的TOS和TTL字段。它还使用探测过程来探索可行的QoS路径。链路度量以可扩展的方式传播，使用路由器子集形成“主导”图。“修复”算法用于动态更新该主导图。支持SQUARN框架的协议和算法将在该项目过程中开发，重点是计算效率和与现有互联网路由协议的向后兼容性。研究议程还包括一个实验组件，用于评估在IP路由器测试平台上提出的解决方案的有效性。除了智力上的优点外，拟议中的项目预计还将产生深远而广泛的影响。无状态QoS路由解决方案的启用将导致实时语音（和视频）应用的成功商业化，导致长途电话速率的显著降低和实时多媒体应用（例如，IP视频电话）的广泛部署。在这个项目过程中开发的解决方案的源代码将被公开发布。拟议项目的各个方面将被整合到亚利桑那大学的本科和研究生课程中。此计划将作为促进学生了解和欣赏网络多媒体应用的工具。

This project is aimed at developing and experimentally evaluating a framework for stateless quality of service routing in IP networks (SQUARN). The need for QoS routing solutions has been recognized in several recent studies and has led to several ongoing efforts to introduce QoS extensions in IP routing protocols. Until now, the work on QoS routing has been carried out under the assumption that the underlying network architecture is reservation based. In such an architecture, routers must maintain per-flow state information and end systems must use explicit signaling messages to convey their QoS requirements. This explicit-reservation model, though attractive from a network control viewpoint, suffers from scalability problems. The proposed SQUARN model is intended to provide stateless QoS routing solutions that can be integrated into reservation-less QoS frameworks (e.g., DiffServ). SQUARN relies on dynamic packet forwarding mechanisms that make novel use of the TOS and TTL fields in the header of an IP packet. It also uses a probing procedure for exploration of viable QoS paths. Link metrics are disseminated in a scalable fashion using a subset of routers that form a "dominating" graph. "Repair" algorithms are used to dynamically update this dominating graph. Protocols and algorithms in support of the SQUARN framework will be developed in the course of this project, with emphasis on computational efficiency and backward compatibility with existing Internet routing protocols. The research agenda also includes an experimental component for evaluating the efficacy of the proposed solutions on a testbed of IP routers.Besides its intellectual merits, the proposed project is expected to have a profound broader impact. The enabling of stateless QoS routing solutions will lead to successful commercialization of real-time voice (and video) applications, resulting in a significant reduction in long-distance phone rates and wide deployment of real-time multimedia applications (e.g., video telephony over IP). The source code of solutions developed in the course of this project will be publicly released. Various aspects of the proposed project will be integrated into undergraduate and graduate courses at the University of Arizona. The project will be used as a vehicle to promote the understanding of and appreciation for networked multimedia applications among students.