Performance study of IP and SONET grooming in optical WDM mesh networks

We study the problem of IP traffic grooming in optical wavelength-division-multiplexed (WDM) mesh networks. Two different grooming architectures are considered: (i) IP/MPLS grooming, and (ii) SONET grooming. The IP/MPLS grooming approach provides a fine level of grooming granularity realized via software-based implementations but has router-processing-related bottlenecks. The SONET grooming approach is realized in dedicated hardware, but it is more expensive and typically offers limited grooming granularity choices. We also consider multipath routing as used in SONET virtual concatenation techniques, and we study the impact of the differential delay constraint. A detailed comparison of the different grooming options in terms of blocking probability, lightpath utilization, and survivability issues is presented. The simulation analysis helps quantify the improved performance of finer granularity grooming approaches over the coarser SONET-based approaches.