Method and system for traffic management in packet networks using random early marking

• US 6,977,943 B2
• Filed: 10/04/2001
• Issued: 12/20/2005
• Est. Priority Date: 10/04/2001
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Tropic Networks, Inc. (Nokia Corporation)
• Inventors: Zboril, Thomas George
• Primary Examiner(s): Pham, Brenda
• Application Number:
  US09/969,785
• Publication Number:
  US 20030067878A1
• Time in Patent Office: 1,538 Days
• Field of Search: 370/229, 370/231, 370/232, 370/235, 370/252, 370/253, 370/358, 370/373, 370/235.1, 370/377, 370/384, 370/385, 370/386, 370/388, 370/395.4, 370/290, 370/360, 370/363, 370/368, 370/371, 370/374, 370/378, 370/381, 370/389, 370/396, 370/398, 370/400, 370/411, 370/413, 370/419, 370/428, 370/429
• US Class Current: 370/429
• CPC Class Codes: H04L 12/5602 Bandwidth control in ATM Networks, e.g. leaky bucket
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames

Abstract

The invention describes a method for traffic management in a packet network using random early marking. For each packet flow, packets are randomly marked at the ingress of the network, while discard of the packets at the egress of the network is performed deterministically, i.e. in accordance with the predetermined rules. The step of random marking includes measuring parameters of the data flow, calculating marking probability by applying a mathematical function to the measured parameters, and generating a mark by applying a random logic function to the calculated marking probability. The packets are dropped at the egress of the network if the corresponding queues where the packets have to be stored are congested or full. A corresponding system for traffic management in packet networks is also provided.

Claims

1. A system for traffic management in a packet network having a plurality of switching stages, the system comprising:

means for randomly marking packets in each packet flow, the means randomly marking comprising one random marker per packet flow at the ingress of the network; and

a plurality of means for deterministically discarding said marked packets in each packet flow, the means for deterministically discarding comprising one or more deterministic packet droppers per each packet flow, the number of the deterministic packet droppers being less than or equal to the number of the switching stages, each packet dropper being disposed after a respective switching stage or at the egress of the network.

2. A system as described in claim 1, wherein the means for marking comprises:

means for determining a measure of the flow at the ingress of the network;

means for calculating a marking probability based on said measure of the flow; and

means for randomly generating a mark based on the calculated probability for marking the packet.

3. A system as described in claim 1, wherein the means for discarding comprises means for dropping the marked packet in response to a signal regarding a status of a queue where the marked packet is to be stored.

4. A method for traffic management in a packet network having a plurality of switching stages, comprising the steps of:

randomly marking packets at the ingress of the network so that packets for each packet flow are marked in one random marker at the ingress of the network associated with the packet flow; and

for each packet flow, deterministically discarding said marked packets in one or more deterministric packet droppers, the number of deterministic packet droppers being less than or equal to the number of the switching stages, each packet dropper being disposed after a respective switching stage or at the egress of the network.