Virtual Network Embedding in Hybrid Datacenters with Dynamic Wavelength Grouping

With ever increasing traffic demands, data enter networks are envisioned to be a hybrid of both optical and electrical networks. In this context, we consider the recently proposed dynamic wavelength grouping (DWG) architecture for the optical network. This architecture can dynamically group wavelengths from different ports onto a single fiber carrying fixed number of wavelength groups. We focus on the joint problem of VM-placement and bandwidth allocation in such a hybrid optical-electrical data enter network with DWG capability. There are multiple challenges: (i) the number of edge-switches that can be simultaneously reached using optical paths from an edge-switch is limited by cost, and (ii) wavelength-group continuity constraint. Abstracting the requests of tenants as virtual networks, we study the novel problem of embedding virtual networks on this hybrid datacenter, which translates to the joint problem of bandwidth allocation and placement such that the requirements of virtual networks are satisfied. We develop and analyse two algorithms for embedding dynamically arriving virtual network demands on a hybrid datacenter with DWG capability. The performance studies demonstrate the effectiveness of exploiting existing optical paths as well as using electrical links in the face of multiple constraints to accept higher number of requests.