Several computer tools addressing the routing and wavelength assignment (RWA) problem are available today within the research community. However, these tools have low flexibility and are difficult to use for remote or casual users. This paper shows how to allow a remote access to various existing RWA tools using Web Services. In this way, software components implementing routing and/or wavelength assignment are turned into Web Services made available over the internet and accessible through a simplified interface. This dispenses the user to perform a local implementation, allows better code reuse, and offers an easy way to confront results from distinct models. Moreover, making tools available on the web increases their credibility and visibility. In our approach, a multilayer network description (MND) format is used to describe both input data and computed results. It offers common basic structure while guaranteeing a large extensibility, and thus makes possible the interaction between various tools. The viability of this approach is illustrated through an example of implementation.