Hierarchical star or rooted tree networks have been implemented and have any desirable characteristics, including excellent performance, conceptual simplicity, and suitability for optical fiber implementations. However, they have a single point of vulnerability to catastrophic failure (the master or root hub) as well as vulnerabilities to single failures of links or hubs high in the hierarchy, which could disable large portions of the network. Redundant network components are added to eliminate this vulnerability and to make an economic but extremely robust and fault-tolerant network, while preserving the advantages of previous hierarchical networks.