Funplace: A Protocol for Network Function Placement

The Network Function Placement (NFP) problem involves placing Virtual Network Functions (VNFs) in a network in order to meet the Service Function Chain (SFC) requirements of the flows through the network. Simultaneously, the usage of network resources by the VNF instances must be optimized. Prior work primarily treated this as a constraint satisfaction problem, using linear programming to find optimal solutions. In contrast, this paper presents a distributed approach, based on a message-passing network protocol. This approach allows network nodes to negotiate the placement of VNF instances. A discrete-event simulation of the protocol is used to demonstrate it as a viable technique. A non-linearly constrained optimization (NCO) formulation is used to find optimal solutions for comparison and it is shown that the protocol yields nearly optimal solutions.