Method for regulating traffic of TCP flow

A method for regulating traffic of a Transmission Control Protocol (TCP) flow includes: deciding, based on a ratio of current bucket level to bucket size, a value of an Explicit Congestion Notification (ECN) bit of a packet; setting a field of a meter tag of the packet based on a packet length of the packet, the value of the ECN bit, and a current bucket level; updating the current bucket level based on the field of the meter tag; calculating an actual transmission rate; and determining an adjustment value based on a difference between the actual transmission rate and a target rate, and adjusting a rate of change of bucket level based on the adjustment value.