The current copper-based communication network is going to be replaced with an optic fiber network. The new technology allows a larger amount of information to be transmitted than before. Due to its bandwidth and relatively high installation cost, however, the optic fiber network does not exhibit the inherent structural redundancy provided by the conventional copper-based network. We propose to supply it by adding multiple paths between important nodes. This so-called network survivability problem is computationally expensive to solve exactly. We report the application of a heuristic algorithm to this problem. Also discussed is the issue of how to make use of existing conduits.