cucsSwEthMonSrcEpMonTrafDir (syntax CucsFabricTrafficDirection) specifies which direction of traffic -- received, transmitted, or both -- is being mirrored through this SPAN source endpoint for monitoring. An admin sets or checks this to make sure the SPAN configuration is capturing the traffic direction actually needed for the analysis being performed, since capturing the wrong direction wastes monitoring capacity and misses the data of interest. For example, an admin troubleshooting one-way packet loss would set this to capture only the receive direction on the suspect port rather than mirroring both directions unnecessarily.