QoS-based routing in optical networks

In this paper two aspects of optical quality of service (QoS), namely the quantitative measures of the optical signal and the functional requirements such as routing stability and protection were discussed. Transmission impairments-based routing of 40 Gb/s connections was investigated and substantial improvement in bandwidth utilization was demonstrated when traffic was split at the source into 10 and 40 Gb/s connections, that were routed separately based on the quality of the available transmission links. The feasibility of differentiation based on routing stability in integrated traffic engineering was demonstrated using the RITE scheme with the preliminary results indicating substantial potential for better utilization of existing lightpaths. Class-based protection and restoration has been investigated and numerical examples were provided that show how different classes of traffic could be routed in a cost-effective way requiring less protection bandwidth.