ITR: Routing of Dynamic Service Level Agreements between Inter-domain Bandwidth Brokers

本研究计划旨在探讨下一代互联网的差异化服务领域中几个尚未解决的问题。特别是，在存在多个替代物理路径的情况下路由SLA的问题是一个很少研究的话题。这是一个重要的问题，因为目标是在不选择过度配置的情况下最大限度地提高SLA的成功概率。此外，在存在多个物理路径的情况下，这在大型网络中是典型的，需要基于适当的标准来选择最优路径。拟议的研究直接解决了这一关键问题。目前，还没有标准的分层QoS路由方案。分层QoS路由中最关键的问题之一是在网络状态信息过时或陈旧的情况下做出智能决策。拟议的研究将解决这个问题，利用本地的统计数据收集在每个路由器，并获得一个时间历史的网络状态信息。此外，每个域将具有有限的业务处理能力。此容量受域拓扑和最大链路带宽的限制。对于计算可行路径，目前的QoS路由方案只考虑单个链路带宽作为约束，而不是作为一个整体的域容量。该研究将解决这个缺点，将域容量作为一个约束的路径计算算法。此外，本研究计画亦将研究以最大化域资源利用率为目标的转接域聚合流分割问题。其动机来自于聚合流的拆分将导致更好地利用网络带宽的事实。

This proposed research project aims to explore several unanswered questions in the area of differentiated services for next generation Internet. In particular, the issue of routing SLAs in the presence of multiple alternative physical paths is a topic that has been seldom researchedupon. It is an important issue since the objective is to maximize the probability of success for an SLA without opting for over-provisioning. Also, in the presence of multiple physical paths, which is typical in large networks, there is a need to choose the optimal path based on appropriate criteria. The proposed research directly addresses this critical issue. Currently, there are no standard schemes for hierarchical QoS routing. One of the most crucial problems in hierarchical QoS routing is to make intelligent decisions in the presence of out-of-date or stale network stateinformation. The proposed research will address this issue by making use of local statistics collected at each router and obtaining a time history of the network state information. Furthermore, every domain will have a finite traffic handling capacity. This capacity is bound above by the domain topology and the maximum link bandwidth. For computing feasible paths, current QoS routing schemes take only the individual link bandwidth into account as a constraint but not the domain capacity as a whole. The research will address this shortcoming by incorporating the domain capacity as a constraint in the path computation algorithms. Additionally, this research project will also study the problem of splitting aggregated flows in a transit domain with the goal of maximizing the domain resource utilization. The motivation comes from the fact that splitting of aggregated flows will lead to better utilization of the network bandwidth.