Queuing closed loop congestion mechanism

A packet switch with at least one queuing congestion mechanism for use in a packet network that includes a plurality of packet switches in communication through a plurality of telecommunications links, the packet switch comprising:

• a plurality of ingress ports, each of the plurality of ingress ports operable to receive packets of information from one of the plurality of telecommunications links of the packet network;
• a plurality of egress ports, each of the plurality of egress ports operable to communicate packets of information to one of the plurality of telecommunications links of the packet network;
• a switch matrix operable to receive packets of information from the plurality of ingress ports, to perform packet switching on the packets of information, and to communicate the packets of information to a designated one of the plurality of egress ports;
• and
• at least one queuing congestion mechanism operable to provide congestion management at one of the plurality of egress ports, the congestion mechanism including:
• a first queue having an input, an output, and a capacity, the first queue operable to receive packets of information of a first type at its input that are destined to be communicated to the egress port through its output,
• a second queue having an input, an output, and a capacity, the second queue operable to receive packets of information of a second type at its input that are destined to be communicated to the egress port through its output,
• a third queue having an input, an output, and a capacity, the third queue operable to receive packets of information of a third type at its input that are destined to be communicated to the egress port through its output,
• a scheduler operable to receive the packets of information from the output of the first queue, the output of the second queue, and the output of the third queue, and to communicate the packets of information to the egress port of the packet switch based on a schedule, and
• a queue shaper operable to set an adjustable rate in which the packets of information of the third queue are communicated to the scheduler, wherein the adjustable rate is controlled by a loading of the capacity of the second queue.

A method for performing queuing closed loop congestion management in a packet switch of a packet network, the method comprising:

• monitoring the loading of the capacity of a first queue, a second queue, and a third queue to hold packets of information communicated through the packet network, each queue associated with an egress port of the packet switch and associated with different levels of service;
• setting an adjustable data rate to communicate the packets of information of the third queue to a scheduler, wherein the adjustable data rate is controlled by the loading of the capacity of the second queue;
• scheduling the communication of the packets of information from the first queue, the second queue, and the third queue to the egress port of the packet switch based on a schedule;
• and
• enabling a discard policy for the third queue based on the loading of the capacity of the second queue.