This field is the average, as frozen at the moment this historical snapshot was taken, of the per-interval delta values for FCoE payload bytes transmitted out this same converged Ethernet uplink toward the fabric, taken across the retained collection history for this stats object. Admins watch this to separate a genuinely sustained problem from one noisy interval — if DeltaAvg for bytesTx on this interface is climbing, comparing this against bytesRx on the same interface shows whether the FCoE conversation is asymmetric, rather than a one-off spike. For example, an average of 254,773 bytes per interval describes this uplink's typical steady-state FCoE throughput between polls.