Multi-layer traffic grooming in networks with an IP/MPLS layer on top of a meshed optical layer

Traffic grooming in networks employing WDM is gaining attention due to the difference between the bandwidth requirements of the traffic demands coming from the client layer and the capacity of a wavelength in an optical transport network (OTN). In this paper an algorithm for efficient traffic grooming in a multi-layer IP/MPLS-over-meshed OTN scenario is presented. It allows designing the IP/MPLS logical topology best suited to deal with the offered traffic pattern, taking into account the unidirectional and maybe asymmetric character of IP traffic. This multi-layer traffic grooming algorithm is based on the idea of charging the IP/MPLS layer for the capacity it consumes in the optical layer. In order to assess its performance, a comparison with other grooming approaches is made. The results show that our method allows for serious savings in the overall network design cost. It also allows for a gradual capacity installation in the network, thus spreading the installation cost.