Algorithms and Protocols for Constrained Path Selection and Fault Monitoring in Packet Networks

Abstract

Efficient resource utilization and fast failure recovery are essential design goals of next-generation backbone networks. The need for efficient resource utilization has motivated the development of various protocols and techniques that offer data services over legacy backbone networks such as Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH). Enabling improved utilization with enhanced network reliability requires various network optimizations, both at the protocol and system levels. In this dissertation, we present a set of network optimization techniques that improve the performance of an end-user connected to classical packet networks such as Internet. First, we introduce an efficient path selection algorithm that enables seamless bandwidth upgrade for an existing Ethernet connection over SONET/SDH backbone using virtual concatenation technique. We also provide a heterogenous concatenation technique that improves the bandwidth utilization and that is easy to maintain. Second, we present a novel failure localization technique, that can detect single-link or simultaneous multiple-link failures. This technique is based on constructing a set of monitoring paths and cycles from one or more monitoring locations in the network. Third, we present an efficient routing and wavelength assignment scheme for backbone networks with stale network-state information. Finally, we present an e±cient server placement scheme for supporting multiple-description-coding (MDC) based media streaming over content delivery networks. We show that by using MDC-encoded media, intelligent server placement, and efficient path selection, the performance of an end-user can be greatly improved.