AbstractInternet traffic engineering is defined as performance evaluation and performance optimisation of operational IP networks. The definition covers both planning and routing optimisation. Planning typically optimises network topology at large time scales. Routing optimisation optimises the routing configuration in the network for a specific traffic matrix, assuming a fixed topology. With automatically switched transport networks the topology provides an additional degree of freedom at time scales on the order of magnitude of those at which traffic engineering operates. Therefore, in such a network, the decision processes should be co‐ordinated. The present contribution describes an approach and algorithms to support such co‐ordinated decisions in a centralised off‐line traffic‐engineering tool. The approach optimises the logical topology and link capacity overlaying the ASTN and the IP routing configuration. It is supported by a simulation