A method in a network controller of a control plane in a software defined network (SDN) coupled to a plurality of network elements (NEs) of a data plane in the SDN is described. The method includes at least sending a first control message to an ingress NE of the plurality of NEs to initiate a first test session; sending a second control message to an egress NE of the plurality of NEs to initiate a second test session; sending the test message to the ingress NE to cause the ingress NE to transmit the outgoing message from the ingress NE; receiving the first reply message from the ingress NE; receiving the second reply message from the egress NE; and calculating an indication of a delay between the ingress NE and the egress NE.