Investigation of cost and spectrum utilization in internet protocol-over-elastic optical networks

Abstract

In the current work, we investigate the cost and the spectrum utilization in an IP-over-elastic optical network (IP-o-EON) by formulating a multiple-layer survivability problem. We formulate novel ILPs to obtain the solutions by considering joint failures, wherein a single step dimensions the network under the consideration of its operation which is normal and also with all the single failures. The ILPs also aim at the following two levels of survivability: (i) single optical link failure and (ii) single optical link, and optical and IP node failure. The simulations are conducted considering realistic network topologies, traffic matrices, and models for cost. The obtained results demonstrate that the proposed combined multiple-layer methods (i) are highly efficient owing to the use of (a) IP grooming capability(s) and (b) primary and backup resource(s) sharing and (ii) result in significant savings of the CapEx. The results also make it evident that there occurs a definite trade-off between CapEx and spectrum utilization in an IP-o-EON since inclusion of failure analysis within the design process results in extra traffic load in various failure states which results in the proposed combined methods demonstrating higher (worst) spectrum utilization.