This read-create integer configures the CIR for queue 3, with 0 signaling that rate shaping is inactive for that queue. This value lets an admin throttle queue 3's traffic to a defined sustained rate, useful for keeping one traffic class from monopolizing the egress port. For example, an admin might set queue 3's CIR to 1000 kbps to cap a guest-network queue well below business traffic's allocation.