NeTS: Small: Collaborative Research:Cross Layer Survivability to Cascading Failures in Layered Networks

波分复用(WDM)光网络构成了所有现代通信网络和系统的关键主干。因此，这些网络的容错设计和运行一直是人们非常感兴趣的问题。在过去十年左右的时间里，文献中出现了一些与容错、保护和恢复问题有关的基本进展。这些进展中的大多数都是在一层失败的背景下取得的。但是，现代通信系统由多个物理实现组成，通过分层协议进行通信。因此，一个层的单个故障可能导致级联故障，即物理层的故障导致逻辑层的故障。这一领域的跨层生存性研究仍处于起步阶段。在这个基础研究项目中，主要研究人员将开展跨层网络生存性研究，以应对分层网络中的级联故障。这项研究将在IP-over-WDM光网络的背景下进行。重点将放在物理(光)层的多个故障及其在更高层(即IP层)的后果上。具体地说，该项目的广泛范围将涵盖i)多故障下的可生存逻辑拓扑映射，ii)保证可生存性的逻辑拓扑映射，iii)多约束下的逻辑拓扑映射，以及iv)跨层流动、可生存逻辑拓扑的能力和相关算法挑战的普遍理论和方法。该项目旨在发展统一的理论和方法，将使我们对跨层可生存性问题的理解取得重大进展，并为未来跨层设计和优化的一般领域的进展提供理论基础。这些理论将基于图论、数学规划(例如网络阻断)和算法设计方面的现代进步。主要研究人员将开发基于先进数据结构和计算机算法的创新算法技术，如近似技术以及跨层流动的广义理论，这将远远超出广泛使用的经典单层流动理论。更广泛的影响：虽然IP-over-WDM网络将为研究提供背景，但将开发的跨层流动理论和算法(特别是近似)技术将具有跨越计算机科学、电气工程、图论和数学编程的多学科价值。这项研究还将在培训高技能研究人员以进行不同信息技术领域尖端技术的研究和开发方面具有重要的教育价值。

WDM (wave-length multiplexing) Optical networks form the critical backbone of all modern communication networks and systems. Therefore, there has been a great deal of interest in the fault tolerant design and operation of these networks. In the past decade or so several fundamental advances relating to the fault tolerance, protection and restoration issues have appeared in the literature. Most of these advances have been in the context of failures in one layer. But, modern communication systems consist of multiple physical implementations communicating via layered protocols. As such, a single failure at one layer may lead to cascading failures, i.e., failures at the physical layer lead to failures at the logical layer. Research in this area of cross-layer survivability is still in its infancy. In this basic research project the principal investigators will carry out a study of network survivability across layers to deal with cascading failures in layered networks. The research will be in the context of IP-over-WDM Optical networks. The focus will be on multiple failures in the physical (optical) layer and their consequences at the higher layer, namely the IP layer. Specifically, the broad scope of the project will cover i) survivable logical topology mapping under multiple failures, ii) Logical topology mapping for guaranteed survivability, iii) Logical topology mapping under multiple constraints, and iv) A generalized theory of flows across layers, capacity of survivable logical topologies and related algorithmic challenges.The project seeks to develop unifying theories and methodologies that will make significant advances to our understanding of cross-layer survivability issues, and providing the theoretical foundation for future advances in the general area of cross-layer design and optimization. These theories will be based on modern advances in graph theory, mathematical programming (e.g., network interdiction) and algorithm design. The principal investigators will develop innovative algorithmic techniques based on advanced data structures and computer algorithms such as approximation techniques as well as a generalized theory of cross layer flows that will go well beyond the widely used classical theory of single layer flows. Broader Impact: Although IP-Over-WDM networks will provide the context for the research, the theory of cross-layer flows and the algorithmic (in particular approximation) techniques that will be developed will have multidisciplinary value spanning computer science, electrical engineering, graph theory and mathematical programming. The research will also have significant educational value in training highly skilled researchers for research and development in cutting edge technologies in different areas of information technology.