Patent ID: 6868065

Claim:
A method for implementing a quality of service policy in a data communications network, comprising: receiving a packet of a certain flow; extracting certain flow information from the packet; using the certain flow information as an index into an active flow table containing at least one active flow to look up quality of service parameters applicable to the certain flow, the quality of service parameters including a contract value specifying a committed access rate corresponding to the certain flow, an output queue corresponding to the certain flow, and an output queue threshold co corresponding to the output queue; using the quality of service parameters to determine a codepoint for the packet, the codepoint having encoded in it the output queue and the corresponding output queue threshold value; implementing a token bucket algorithm with respect to the certain flow using the contract value and a leak rate to determine whether the packet is in-profile or out-of-profile; and when the packet is out-of-profile; modifying the codepoint for the packet and determining whether the packet is to be drooped; and when the packet is in-profile or when the determination has been made that the packet that is out-of-profile is not to be drooped: directing the packet to the output queue based on the codepoint and setting the output queue threshold of the output queue based on the codepoint.