This read-create INTEGER, in bits per second, sets the committed rate that the port shaper smooths egress traffic down to, and is not applicable when the shaper is disabled. An admin sets this to the actual sustained rate they want the port's outbound traffic shaped to, matching it to a downstream link's real capacity to avoid overwhelming it. For example, an admin shaping a port connected to a 10 Mbps WAN circuit would set this CIR value to 10,000,000 bps so the switch smooths its output to match that circuit's rate.