Patent ID: 9537741
Date: 2017-01-03
CPC Classifications: H04L

Claim:
1. 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, comprising: sending a first control message to an ingress NE of the plurality of NEs to initiate a first test session, wherein content of the first control message instructs the ingress NE to respond to an incoming test message sent from the network controller and received by the ingress NE with transmission of a first reply message to the network controller and with transmission toward a destination NE of an outgoing test message from the ingress NE, wherein the destination NE is in the SDN and is downstream from the ingress NE, and wherein the ingress NE is a first edge NE within the SDN; sending a second control message to an egress NE of the plurality of NEs to initiate a second test session, wherein content of the second control message instructs the egress NE to respond to an incoming test message sent from an upstream NE and received by the egress NE with transmission of a second reply message to the network controller, wherein the egress NE is a second edge NE within the SDN; sending the test message to the ingress NE to cause the ingress NE to transmit the outgoing test message from the ingress NE, wherein the outgoing test message from the ingress NE causes the receipt of the incoming test message received by the egress NE; receiving the first reply message from the ingress NE, wherein the first reply message includes a first set of one or more timestamps, the first set of timestamps including a first received timestamp that indicates the time when the ingress NE received the incoming test message received by the ingress NE; receiving the second reply message from the egress NE, wherein the second reply message includes a second set of one or more timestamps, the second set of timestamps including a second received timestamp that indicates the time when the egress NE received the incoming test message received by the egress NE; calculating an indication of a delay between the ingress NE and the egress NE based on a difference in time between one timestamp of the first set of timestamps and one timestamp of the second set of timestamps; and rerouting network traffic between the ingress NE and the egress NE in response to a determination that the indication of the delay between the ingress NE and the egress NE exceeds a threshold value.