Joint defragmentation of spectrum and computing resources in inter-datacenter networks over elastic optical infrastructure

In this paper, we consider to apply a joint defrag-mentation (DF) of spectrum and computing resources in the inter-datacenter (inter-DC) networks built over elastic optical infrastructure based on the optical orthogonal frequency-division multiplexing (O-OFDM) technology. We propose joint DF algorithms that consist of a request selection strategy to select active requests for reconfiguring and an anycast-based DF routing and spectrum assignment (DF-RSA) to reconfigure the selected requests. For the joint DF, two request selection strategies and three anycast-based DF-RSA schemes are designed, and their combinations are evaluated with simulations. The simulation results show that by considering the usages of spectrum and computing resources jointly, the proposed algorithms can improve the blocking performance of the inter-DC network significantly with controlled numbers of DF operations.