Designing networks which can provide more and more bandwidth is a daunting and continuous effort. All-optical networks are one of the most successful recent approaches to tackle with that need although they come with some inconveniences. One of such problems is the need to design networks that will be able to cope with existing and future demands with the least possible hardware deployment, especially without having to resort to costly frequency conversion or opto-electronic conversion.

In this work we deal with this problem, named RWA-SLE, by encoding it as a pseudo-Boolean satisfiability problem. Then we compare results using our solving method with other proposed approaches for a wide range of generated problem instances. Results show that, for those problems where it is hard to find a suitable set of routes and wavelength assignments our method performs better than other methods. Solving those hard instances is particularly interesting because, otherwise, more hardware deployment would be needed to meet the traffic requirements.