This paper proposes an approach to support end-to-end quality of service over IPv6 networks. In our solution, IPv6 flow labels are used to give better performance into the process of packet classification on network routers. In order to evaluate our proposal, a router model is obtained and it is compared with other technologies as IntServ and MPLS. As result, we obtain a solution with benefits of QoS support and label switching in IPv6 routers.