In this paper we formulate an integer programming model to solve the problem of dimensioning a dynamic WDM optical network taking into account the link capacity as well as the number of transmitters and receivers required in each node. Previous work has only considered the dimensioning of links. The objective function is minimizing the network cost as a function of the link capacity and the number of transmitters/receivers in each node. The constraint is given by the target blocking probability that all connections must meet. Results show that, compared to the classical approach of dimensioning just the link capacity, the proposed dimensioning method achieves a significantly lower network cost by decreasing the capacity required in the network links as well as the number of transmitters and receivers in the network nodes. In the cases studied, at low traffic loads the number of transmitters/receivers required in the network was as low as the half of the number obtained by a dimensioning that only takes the number of wavelengths into account.