What is SNDlib?

SNDlib is a library of test instances for Survivable fixed telecommunication Network Design. Its purpose is

To this end, the library includes a set of network design instances together with the best known solutions and dual bounds, a list of conferences related to this area, and a mailing list.

People behind SNDlib

SNDlib has officially been announced at the DRCN 2005 conference by Michał Pióro from Warsaw University of Technology and Roland Wessäly from atesio and ZIB, and many people have helped building up the library by providing network design instances or by doing programming work. SNDlib is currently maintained at ZIB by Christian Raack and Kai Hennig with help from Sebastian Orlowski and Roman Klähne (atesio).


We hope that it will become a future standard that proposers of new network optimization algorithms will use a representative subset of the SNDlib instances to illustrate the effectiveness of their approaches and compare them with other, already existing algorithms. To achieve this, researchers and practitioners working in the area of fixed network design are cordially invited to contribute to the SNDlib in order to increase its usefulness (see below for details on how to contribute).

Why SNDlib?

In the field of telecommunication network design problems, proposed solution approaches range from LP-/IP-based models and algorithms such as branch-and-bound, row and column generation, or Lagrangian relaxation to meta-heuristics such as evolutionary algorithms, simulated annealing and tabu search.

For devising credible conclusions on the competitiveness of a particular modeling or algorithmic approach, it is highly desirable to have a set of representative, challenging and referenceable test instances at hand on which the new algorithm can be compared to other approaches. Unfortunately, such comparisons are rare, also due to the lack of publicly available but realistic data sets. This is in contrast to other areas where libraries of standardized test instances are available. Examples are the MIPLIB for mixed-integer linear programs, the TSPlib for the Traveling Salesman Problem, or the FAP Web for frequency assignment problems in mobile phone networks.

The goal of the SNDlib is to provide and maintain such a library of network instances for various fixed network design problems. The library contains a list of problems and their solutions provided by practitioners who are professionally involved in network design, as well as by researchers working on the theory or practice of network design models and algorithms. Given the enormuos variety of network design problems, we intend to extend the library step by step. In the current version, we have deliberately limited the scope to single-layer network design problems with single-link failures. Extensions such as several demand matrices per network, a more detailed description of node hardware, or an integrated design of several network layers are planned for subsequent phases.

How can I contribute?

The SNDlib can only be useful to the network design community if it is kept up to date and enhanced by its users. Every user can contribute, but the site is moderated to keep it structured and, in particular, referenceable. You can help increasing the usefulness of the SNDlib in a number of ways:

Total profit over all SNDlib users is maximized if every user contributes a little bit in any of the above ways. By sharing your knowledge and resources with the network design community, everybody will profit from it, including yourself!

© 2006 Zuse-Institute Berlin (ZIB)