This read-only integer is the unique identifier assigned to a specific bridge port, ranging from 1 up to the sum of the configured group and LAN interface counts on the unit. An administrator uses it purely as the index to correlate a row of per-port bridge statistics with the physical port or group it describes. For example, when reading a table of bridge port counters, the administrator would use statBridgePortIndex to match an unusually high error count back to the specific group interface causing it.