Joint Optimization of IT, IP and WDM Layers: From Theory to Practice

Softwarization of carrier networks is an unstoppable trend, driven by the possibility of instantiating Virtual Network Functions (VNFs) in carrier-owned data centers in their points-of-presence. In optical networks, VNF placement decisions are now intrinsically tight to IP and WDM resource allocations, e.g. in the metro, moving a VNF to a different central office changes the IP flows to carry, which then impacts the optical circuit footprint. In this paper, we review the efforts for a joint or cooperative optimization of the IT, IP and optical resources, both from the offline capacity planning and the online resource allocation points of view. The paper covers both theoretical results and practical implementation initiatives. Among them, we further elaborate on the Metro-Haul project approach, that proposes a common simulation framework for algorithm development and testing, which allows the application of those algorithms in demonstration prototypes.