ITR: Stateless Quality of Service Routing in IP Networks

本项目旨在开发和实验评估IP网络中的无状态服务质量路由框架(SQUARN)。最近的几项研究已经认识到了对Qos路由解决方案的需求，并导致了几项正在进行的在IP路由协议中引入Qos扩展的努力。到目前为止，关于服务质量路由的工作一直是在假设底层网络体系结构是基于预约的基础上进行的。在这样的体系结构中，路由器必须维护每个流的状态信息，并且终端系统必须使用显式信令消息来传达其服务质量要求。这种显式预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。所提出的SQUARN模型旨在提供可被集成到无预留服务质量框架(例如，DiffServ)中的无状态服务质量路由解决方案。SQUARN依赖于动态分组转发机制，该机制新颖地利用了IP分组报头中的TOS和TTL字段。它还使用探测过程来探索可行的服务质量路径。使用路由器的子集以可伸缩的方式传播链路度量，所述路由器子集形成了一个“主导”图。“修复”算法被用来动态更新这个主导图。在该项目过程中，将开发支持SQUARN框架的协议和算法，重点是计算效率和与现有因特网路由协议的向后兼容性。研究议程还包括一个实验部分，用于在IP路由器的试验台上评估所提出的解决方案的有效性。除了其智力优势外，拟议的项目预计将产生深远的更广泛的影响。无状态QoS路由解决方案的启用将导致实时语音(和视频)应用程序的成功商业化，从而显著降低长途电话费率并广泛部署实时多媒体应用程序(例如，IP视频电话)。在这个项目过程中开发的解决方案的源代码将公开发布。拟议项目的各个方面将被纳入亚利桑那大学的本科生和研究生课程。该项目将作为一种工具，促进学生对网络多媒体应用的理解和欣赏。

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.