Random early detect and differential packet aging flow in switch queues

• US 20060265424A1
• Filed: 07/28/2006
• Published: 11/23/2006
• Est. Priority Date: 01/06/2004
• Status: Active Grant

• Current Assignee: Maxlinear Incorporated
• Original Assignee: Lantiq Deutschland GMBH (Intel Corporation)
• Inventors: Koo, Hong Lee, Yong, Yean Kee
• Granted Patent: US 7,756,977 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames

Abstract

Flow control is provided for a packet switch. An incoming packet is classified according to its priority based on predefined rules to produce a weight value based on the priority of the packet. A lifetime value associated with the packet is produced based on the weight value and the queue occupancy in a queue to which the packet is assigned. The packet is discarded if its associated lifetime value is less than or equal to a threshold value. Otherwise the packet and associated lifetime value are sent to the queue. The lifetime value is periodically changed and compared to a threshold value. The packet is removed from the queue when its lifetime value reaches the threshold value.

Claims

1. A packet switch comprising:

a packet classification engine for classifying an incoming packet according to its priority based on predefined rules to produce a lifetime value associated with the packet;

a queue for receiving the packet and associated lifetime value;

an aging engine for periodically changing the lifetime value of the packet in the queue; and

a comparator for comparing the changed value to a threshold value to remove the packet from the queue based on the comparing.

2. The packet switch of claim 1, wherein the packet classification engine determines a weight value based on the priority of the packet;

and further comprising a random early detect engine for;

producing the lifetime value based on the weight value and the queue occupancy in a queue to which the packet is assigned; and

discarding the packet if its associated lifetime value is below the threshold value.