The rest of this paper is structured as follows. In Sec. II we discuss the related work. The physical network model, the VNF request model, and ILP problem formulation are presented in Sec. III. The VNF placement heuristics and its evaluation are presented in Sec IV and in Sec. V. The proof–of–concept is presented in Sec VI while some illustrative VNFs and their evaluation are presented in Sec. VII. Finally, Sec. VIII draws the conclusions pointing out the future work.