We provide information on the Survivable Network Design Library (SNDlib), a data library for fixed telecommunication network design that can be accessed at http://sndlib.zib.de. In version 1.0, the library contains data related to 22 networks which, combined with a set of selected planning parameters, leads to 830 network planning problem instances. In this paper, we provide a mathematical model for each planning problem considered in the library and describe the data concepts of the SNDlib. Furthermore, we provide statistical information and details about the origin of the data sets.

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In this article, we study capacitated network design problems. We unify and extend polyhedral results for directed, bidirected, and undirected link capacity models. Valid inequalities based on a network cut are known to be strong in several special cases. We show that regardless of the link model, facets of the polyhedra associated with such a cut translate to facets of the original network design polyhedra if the two subgraphs defined by the network cut are (strongly) connected. Our investigation of the facial structure of the cutset polyhedra allows to complement existing polyhedral results for the three variants by presenting facet-defining flow-cutset inequalities in a unifying way. In addition, we present a new class of facet-defining inequalities, showing as well that flowcutset inequalities alone do not suffice to give a complete description for single-commodity, single-module cutset polyhedra in the bidirected and undirected case -in contrast to a known result for the directed case. The practical importance of the theoretical investigations is highlighted in an extensive computational study on 27 instances from the Survivable Network Design Library (SNDlib).

This survey deals with computational complexity of column generation problems arising in the design of survivable communication networks. Such problems are often modeled as linear programs based on noncompact multicommodity flow network formulations. These formulations involve an exponential number of path-flow variables, and therefore require column generation to be solved to optimality. We consider several path-based protection and restoration mechanisms and present results, both known and new, on the complexity of the corresponding column generation (also called pricing) problems. We discuss results for the case of single link or single node failures scenarios, and extend the considerations to multiple link failures. Further, we classify the design problems corresponding to different survivability mechanisms according to the structure of their pricing problem. Eventually, we show that almost all the encountered pricing problems are hard to solve for scenarios admitting multiple failures, while a great deal of them are N P-hard already for single failure scenarios.