Reports the current number of active connections tracked in this gateway's connection table. This is the real-time load figure an admin watches against fwConnTableLimit to judge how close the gateway is to exhausting its connection capacity, which manifests as new connections being refused once the ceiling is hit even though the gateway otherwise looks healthy. Example: fwNumConn sitting at 90% of fwConnTableLimit during a traffic surge is the early warning that lets an admin act before new-connection failures actually start.