This read-create Unsigned32 specifies the lower 32 bits of an additional CIR increment on top of a port-level QoS shaper's base committed rate. Administrators use it to grant a temporary or supplemental rate boost to a port's shaper without altering the primary CIR configuration. For example, provisioning a short-term promotional speed boost for a customer's port would populate this additional CIR field rather than the base CIR objects.