This counter tracks how many frames arriving on a Frame Relay port carried the FECN (Forward Explicit Congestion Notification) bit already set. A climbing count tells an administrator that congestion exists somewhere further along the network path in the same direction the traffic is flowing, since intermediate switches mark FECN to warn downstream equipment. For example, a support engineer troubleshooting sluggish throughput on a branch circuit would check this counter to confirm the slowdown originates in the carrier's cloud rather than on the local card.