Economic analysis of robust access network architecture in two-tierdata networks

Recent studies have addressed routing and performance issues of nonhierarchical and hierarchical backbone packet networks in a unified fashion, by adopting an end-to-end mean delay objective and including a variety of practical routing constraints. The authors build on this approach to include the design of robust access networks, and they analyze the economic and robustness-related tradeoffs of several access network architectures in two-tier data packet networks. Two-tier architectures consist of an access network that homes to a high-capacity backbone network through a variety of topological arrangements. The access tier provides protocol handling and traffic concentration. The backbone tier performs high-speed transport and alternate routing under congestion/failure conditions. They identify the fundamental access network parameters that allow them to develop network designs with optimized characteristics. The analysis demonstrates the cost effectiveness of access diversity as well as the enhanced robustness it can provide even though it requires higher switch functionality and cost