A communication system includes a flow collector that collects traffic of an NW edge accommodating CPE, an NFVO that provides an instruction to add or remove a resource of a VNF, a resource management device that notifies the NFVO of an increased or decreased resource amount and an addition or removal instruction of the VNF based on an increase or decrease of the traffic of the NW edge collected by the flow collector, and that decides on the VNF which becomes a redirection destination of the traffic of the NW edge in response to execution of addition or removal of the VNF by the NFVO, a VIM that adds or removes the VNF in accordance with an instruction from the NFVO, and a flow controller that instructs the NW edge to set the VNF decided by the resource management device as the redirection destination of the traffic.