Routing and Scheduling Issues in Support of Advance Reservations

该提案的一般主题是集成分组网络中的高级保留。 预先保护分布式应用程序所需资源的能力变得越来越重要。 这不仅对于需要同时访问几个设施和复杂设备的高端科学或医学应用是真实的，而且对于诸如视频会议之类的更普通的应用也是真实的，其合理的高资源要求使得期望确保必要的网络资源与会议参与者同时可用。 对预先预留的支持涉及多个方面，例如对协议的扩展，特别是预留（信令）协议，以及增强的资源管理过程，例如，叫入院。 虽然有一些以前的作品解决这两个方面，相应的两组问题通常被单独考虑。 此外，已经使用的提前预订模型基本上集中在单一服务模型上，即，从给定的开始时间起，在给定的持续时间内（在开始时间和持续时间中可能具有随机分量），给定数量的资源的可用性。 因此，本提案的目标是联合调查协议扩展和资源管理的增强，以及考虑更多的一般服务模式，提前预订。 特别是，研究人员将考虑提前预留请求的路由问题的范围内扩展到OSPF协议，其中链路状态更新已扩展到不同的时间间隔进行资源可用性信息。 这允许分布式实现，其通过避免将所有提前预订请求转发到中央服务器来提高可伸缩性。 然而，它引入了新的问题，以便在确保足够的性能的同时包含协议流量的相应增加。 在这种情况下，研究人员将研究与信息准确性和路由性能之间的权衡相关的问题，并研究使用抢占优先级等机制为应用程序提供一系列服务选项，例如，请求低优先级的大量带宽以及高优先级的少量带宽。 此外，研究人员还将再次结合相关的路由问题考虑高级预订模型的各种扩展，例如最小化完成时间，最大化可用带宽等，这对于能够根据可用服务修改其行为的自适应应用程序来说是潜在的兴趣。 研究人员认为，联合开发必要的基础设施，例如，OSPF协议的扩展，以及对传统的预先预留模型的期望扩展的研究，将使他们在我们对支持预先预留的固有复杂性的基本理解以及我们部署这种能力的能力方面取得重大进展。

The general topic of the proposal is advanced reservations in itegrated packet networks. The ability to secure in advance the resources needed by a distributed application is becoming increasingly important. This is true, not only for high-end scientific or medical applications which require simultaneous access to several facilities and pieces of sophisticated equipment, but also for more mundane applications such as video-conferencing, whose reasonably high resources requirements make it desirable to ensure that the necessary network resources are available at the same time as the conference participants are. Support for advance reservations involves multiple aspects such as extensions to protocols, and in particular reservation (signalling) protocols, and enhanced resource management procedures, e.g., call admission. While there has been a number of previous works addressing both of these aspects, the corresponding two sets of issues have typically been considered separately. In addition, the advance reservation models that have been used, have essentially focused on asingle service model, i.e., the availability of a given amount of resources, from a given starting time, and for a given duration (with possibly a random component in both the starting time and the duration). The goals of this proposal are, therefore , to investigate jointly protocol extensions and enhancements to resource management, as well as consider more general service models for advance reservations. In particular, the researchers will consider the problem of routing of advance reservation requests in the context of an extension to the OSPF protocol, where link state updates have been extended to carry resource availability infromation over different time intervals. This allows for a distributed implementation which improves scalability by avoiding that all advance reservation requests be forwarded to a central server. However, it introduces new problems in order to contain the corresponding increase in protocol traffic while ensuring adequate performance. In that context, the researchers will study issues related to the trade-off between information accuracy and routing performance, and also investigate the use of mechanisms such as preemption priorities to offer applications a range of service options, e.g., request large amount of bandwidth at a low priority together with a small amount at a high priority. In addition, the researchers will also consider, again jointly with the associated routing problem, various extensions to the advanced reservation model, such as mininmizing completion time, maximizing available bandwidth, etc., that are of potential interest to adaptive applications that can modify their behavior according to the available service. The researchers believe that the joint development of the necessary infrastructure, e.g., extensions to the OSPF protocol, and the investigation of desirable extensions to the traditional advance reservation model, will allow them to make significant progress in both our basic understanding of the inherent complexity in supporting advance reservation, and our ability to deploy such capabilities.