QoS in GMPLS based IP/DWDM Metro Networks

Due to the unpredictability of IP traffic, MANs are migrating from SONET/SDH ring architectures to DWDM mesh infrastructures. Firstly, the fast advance in optical technologies has provided DWDM networks with extremely high bandwidth capability (i.e. OC-192 and OC-768). Secondly, Generalized Multi Protocol Label Switching (GMPLS) and Multilayer Traffic Engineering (MTE) paradigms have turned them into highly flexible, scalable and cost efficient infrastructures able to improve service provider's return on investment (ROI). With the GMPLS automated control plane, IP/DWDM networks can take advantage of a better integration between the electrical and optical domains and consequently of a more optimized resource usage. GMPLS enables network-state-depended dynamic routing and grooming and provides network operators with the tools to differentiate service types and increase the offered QoS. This paper discusses the benefits of GMPLS as an integrator paradigm in IP/DWDM metro infrastructures and proposes a QoS control framework which allows a network operator to accommodate MPLS/DiffServ traffic on different virtual topologies that can guarantee different QoS levels. The benefits of GMPLS/MTE and of the proposed scheme are discussed by means of simulation results.