Cost-Oriented VNF Placement for Load Balance

Network function virtualization (NFV) is a technique to decouple network functions from hardware and convert them to software appliances, namely virtual network functions (VNFs). Network services are carried out through service function chains (SFCs), each with some VNFs. Given SFCs and physical machines (PMs), this paper designs a cost-oriented VNF placement (COVP) method to assign each SFC’s VNFs to PMs, with the objectives of maximizing served VNFs, balancing loads of PMs, and saving the total link cost to run SFCs. COVP allocates a PM for each VNF according to its position in the SFC as well as the PM’s resource usage status. If a PM is busy, some VNFs are moved to other PMs in the vicinity for load balance. Both placement and movement of VNFs take link costs into account. Simulation results demonstrate that COVP can achieve the objectives efficiently.