This field is the average, as frozen at the moment this historical snapshot was taken, of the per-interval delta values for FCoE (Fibre Channel over Ethernet) payload bytes received on this converged network adapter's Ethernet uplink, 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 bytesRx on this interface is climbing, a rising rate here confirms storage traffic is actually flowing over the FCoE-encapsulated link rather than sitting idle or being routed elsewhere, rather than a one-off spike. For example, an average of 76,516 bytes per interval describes this uplink's typical steady-state FCoE throughput between polls.