Compute followed by network load balancing procedure for embedding cloud services in software-defined flexible-grid optical transport networks

摘要

A method entails an efficient procedure, namely Compute followed by Network Load Balancing (CNLB), that first maps virtual nodes over physical nodes while balancing computational resources of different types, and finally, maps virtual links over physical routes while balancing network spectral resources.

主权项

1. A method comprising the steps of:
implementing by a computer an embedding of cloud demands over a software defined flexible grid optical transport network, the implementing comprising: determining required resources for each node and arranging virtual nodes in the network in a descending order of a total number of required resources; mapping the virtual nodes over physical nodes while balancing a load for different types of resources; estimating spectral resources for each link and arranging virtual links in a descending order of estimated spectral resources; mapping virtual links over physical routes and selecting a modulation format for the virtual links while balancing the load over physical links; assigning wavelength and spectrum to the virtual links; and selecting a virtual node VN from the top of a list, determining a set of feasible modulation formats for each of a k-shortest routes connecting physical nodes PNs on which virtual nodes VNs are mapped based on their reachability requirements and the requested line rate; finding a bit-map of each of the k-shortest routes connecting PNs on which VNs are mapped, a bit-map of a route being determined by performing bit-wise logical end operations on the bit-maps of all physical links along the route, for each modulation format; determining the total required spectrum, determining a probability of mapping the VL on a route using a modulation format based on a ratio of the number of wavelength slots starting from which consecutive wavelength slots are available for a modulation format on the bit-map of a route k to the total number possible wavelength slots starting from which consecutive wavelength slots can be mapped; and selecting a route and modulation format that has a maximum probability for the virtual link VL, and checking whether the maximum probability is 0 or not.