Adaptive Joint Optimization of IT Resources and Optical Spectrum Considering Operation Cost

Abstract

We propose an adaptive joint optimization method of IT resources and optical spectrum under time-varying traffic demand in elastic optical networks while avoiding an increase in operation cost. Currently, numerous network services are provided by a service function chain (SFC). Once SFCs are provisioned, an optical path is established to connect the SFC and users. SFCs are placed in one of the candidate datacenters in the network by considering residual IT resources and the location of users. Here, the optimal placement of SFCs can vary due to service demand changes. To maintain network performance, we need to reconfigure network configuration by migrating SFCs and rerouting optical paths. However, such reconfiguration requires additional operation cost. In this paper, we consider the joint optimization problem of IT resources and optical spectrum in consideration of operation cost. We formulate the problem as mixed integer linear programming and then quantitatively evaluate the trade-off relationship between the optimality of reconfiguration and operation cost. We demonstrate that we can achieve sufficient network performance through the adaptive joint optimization while suppressing an increase in operation cost.