SNDlib is a library of test instances for Survivable fixed telecommunication Network Design. Its purpose is to make realistic network design test instances available to the research community, to serve as a standardized benchmark for testing, evaluating, and comparing network design models and algorithms, to be a source of information and resources related to fixed network design, and to provide a contact platform for researchers and practitioners working in this field. 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.