Somport can be reached from Jaca, but also from Pau in Southern France. Take a train or plane to Pau and take the regular bus whih leaves from the train station to Oloron St Marie or to Somport. From there you can reach Jaca in one day (its all down), then Arres, Artieda, Izco, Tiebas, Puente la Reina. The refuges in Aragon are good.
You can also walk the northern route past Berdun, but facilities will be less abundant. Helpful Medical Center in Berdun though!
You can also walk the northern route past Berdun, but facilities will be less abundant. Helpful Medical Center in Berdun though!