ITR: Network and Traffic Engineering for DiffServ MPLS-Based Networks

区分服务(DiffServ)和多协议标签交换(MPLS)技术的组合使用是在有效利用网络资源的同时在IP网络中提供服务质量(Qos)的一种很有前途的方法。然而，为了在MPLS网络上有效地承载DiffServ业务，需要在DiffServ类和LSP之间进行映射。此外，这种网络的设计和管理是成功提供服务质量的关键，它包括几个开放的研究问题。在设计网络规划和管理方法时，需要考虑网络流量的高度不可预测性。我们的建议是一项全面的研究，描述了MPLS网络规划以及带宽和路由管理的实用解决方案，它们是协同工作的。提出的想法是允许MPLS网络调整其状态以提供可能的最佳性能和资源利用率的新颖范例。我们建议设计、评估和微调这些新想法。在该项目的带宽管理部分，将设计新的LSP设置、大小、抢占和容量分配方法。路由管理研究包括新的LSP路由算法和带宽请求路由算法。最后，在网络规划研究中，我们将研究基于预测流量负载和长期服务等级规范(SLS)合同来设计最优MPLS网络拓扑及其规模的方法。为了说明上述研究主题的相互关系，考虑网络规划方法已经提供了MPLS网络的初始拓扑的场景。可能的事件包括LSP建立请求的到达或带宽请求的到达。第一个事件可以通过组合使用我们提出的三种方法来处理，依次是：LSP路由、LSP抢占和LSP容量分配。LSP路由的目的是在物理网络上找到将在其上路由LSP的路由。LSP抢占决定在没有足够可用带宽的情况下，是否可以在路由上抢占任何现有的LSP，以便为新的LSP让路。LSP容量分配方法试图微调LSP容量以避免未使用的预留带宽。带宽请求的到达触发了LSP的建立和调整，进而触发了路由、抢占和容量分配的LSP创建步骤。该提议的潜在影响是开发了新的实用方法，这些方法目前在基于DiffServ的MPLS网络的设计和管理中是一个悬而未决的问题。多协议标签交换网络管理的研究已经取得了显著的进展和贡献。这项先前的工作将有助于实现拟议的目标。

The combined use of the Differentiated Services (DiffServ) and Multiprotocol Label Switching (MPLS) Technologies is a promising way to provide Quality-of-Service (QoS) in IP networks, while effectively using network resources. However, to efficiently carry DiffServ traffic over an MPLS network, a mapping between DiffServ classes and LSPs is needed. Moreover, the design and management of such a network is a fundamental key to the success of the QoS provisioning and it includes several open research issues. Many problems need to be solved such as LSP dimensioning, set up tear down procedures, routing, adaptation to actual carried traffic, preemption, initial definition of the network topology, etc. Furthermore, in designing network planning and management methods, we have to take into account the high unpredictability of the Internet traffic.Our proposal is a comprehensive study that describes practical solutions for MPLS network planning along with bandwidth and route management, which interwork in a synergetic fashion. The presented ideas are novel paradigms that allow MPLS networks to adapt their state to provide the best possible performance and resource utilization. We propose to design, evaluate and fine-tune these new ideas. In the bandwidth management portion of the project, new methods for LSP setup, dimensioning, preemption, and capacity allocation will be designed. The route management research includes novel algorithms for LSP routing and bandwidth request routing. Finally, in the network planning research we will investigate methods to design the optimal MPLS network topology and its dimensioning based on predicted traffic loads and long term Service Level Specification (SLS) contracts.To illustrate the inter-relations of the above mentioned research topics, consider a scenario where network planning methods have provided an initial topology of the MPLS network. Possible events include the arrival of a request for LSP setup or arrival of a bandwidth request. The first event can be handled by the combined use of three of our proposed methods, in the order: LSP routing, LSP preemption, and LSP capacity allocation. The LSP routing aims to find the route on the physical network over which the LSP will be routed. LSP preemption decides if any existing LSPs can be preempted on the route to make way for the new LSP in the case in which there is not enough available bandwidth. The LSP capacity allocation method tries to fine tune the LSP capacity to avoid unused reserved bandwidth. The event of arrival of a bandwidth request triggers the LSP setup and dimensioning, which may in turn trigger the LSP creation steps of routing, preemption and capacity allocation.The potential impact of this proposal is the development of novel and practical methods which currently are open issues in the design and management of DiffServ-based MPLS networks. Significant progress and contributions to the study of MPLS network management have already been made in our publications. This previous work will be useful towards achieving the proposed objectives.