  Network Function Virtualization (NFV) is enabling the softwarization of
traditional network services, commonly deployed in dedicated hardware, into
generic hardware in form of Virtual Network Functions (VNFs), which can be
located flexibly in the network. However, network load balancing can be
critical for an ordered sequence of VNFs, also known as Service Function Chains
(SFCs), a common cloud and network service approach today. The placement of
these chained functions increases the ping-pong traffic between VNFs, directly
affecting to the efficiency of bandwidth utilization. The optimization of the
placement of these VNFs is a challenge as also other factors need to be
considered, such as the resource utilization. To address this issue, we study
the problem of VNF placement with replications, and especially the potential of
VNFs replications to help load balance the network, while the server
utilization is minimized. In this paper we present a Linear Programming (LP)
model for the optimum placement of functions finding a trade-off between the
minimization of two objectives: the link utilization and CPU resource usage.
The results show how the model load balance the utilization of all links in the
network using minimum resources.
