Unique number assigned to each flow within PVC. The highest index is 7 upstream and 3 downstream. Please note that flowIndex affects priority scheduling and buffer arbitration. Even when DRR scheduling is requested, flowIndex determines probability of packets being discarded from queue during congestion. Higher flowIndex means higher probability of being discarded. Range 0-3 downstream, 0-7 upstream. In the upstream direction flowIndex is the outgoing p-bit value, with exception for the case that all p-bit values are collected in one flow, in which case the flowIndex value is 0.