A service commonly offered by telecom operators is the Virtual Private Network (VPN) that allows the interconnection of corporate networks in different geographic localities. To deploy this service, an operator, usually, installs in customer's premises some equipments, such as a router and/or a switch. This deployment increases cost and the complexity of the service. By taking advantage of Software Defined Networking (SDN) and Network Function Virtualisation (NFV), this work presents and details a VPN service architecture that decreases Capital Expense (CAPEX) and Operating Expense (OPEX) and it is open to new innovative service offerings, such as: Quality of Service (QoS) policies, Network Address Translation (NAT) and a multi-homing function. This work also contributes to this research area by going further in the description of a real use case at a carrier network.