This paper highlights a practical approach for management and orchestration (MANO) of Network Function Virtualization (NFV) based on Open Source MANO (OSM). We have proposed a testbed that uses the Open Source Orchestration Platform for OSM to manage and orchestrate Voice over Internet Protocol (VoIP) Our testbed has two Virtual Infrastructure Managers (VIMs, OpenStack) logically located in a separate area, which places us in a Wide Area Network (WAN) context. The concept of Software-Defined Networking (SDN) has been implemented through an Open Network Operating System (ONOS) controller managing the traffic between the different VIMs. Our experiments show that the solution is feasible, with latency, jitter, packet loss and Mean Opinion Score all within the required range.