Distributed Computing Column

The undisrupted operation of logical structures and services is a crucial requirement in modern day communication networks. As the vertices and edges of the network may occasionally fail or malfunction, it is desirable to make those structures robust against failures. Fault-Tolerant (FT) Logical Network Structures are low cost high resilient structures, constructed on top of a given network, that satisfy certain desirable performance requirements concerning, e.g., connectivity, distance or capacity. In this survey, we review some recent results for designing FT network structures. We classify the existing construction algorithms into four classes and discuss the settings in which a given approach might become useful. We hope that this would pave the way towards the development of a more generalized theory for the design of fault-tolerant networks.