Juniper Networks, Inc.

3com Corporation

Paul J Giacobbe

John C Carney

Thomas A Lemaire

Michael E Lipman

Ryan Ross

David Lipschutz

John A Flanders

William D Townsend

David C Ready

Robert P Ryan

Leonard Schwartz

A method may include receiving a data unit and identifying a state of a memory storing data units. The method may include selecting a threshold value having a first threshold unit or a second threshold unit based on the state of the memory. The method may include comparing the threshold value to a queue state using the first threshold unit if the memory is in a first state. The method may include comparing the threshold value to the queue state using the second threshold unit if the memory is in a second state.

Dynamic queue management

A method and a network device for sharing bandwidth among a group of classes of traffic for an interface are provided. Bandwidth may be allocated to at least one traffic class of a first priority for the interface. At least some unused bandwidth of the at least one traffic class may be allocated to at least one other traffic class of a second priority for the interface. In some implementations, weighted constituents may be allocated unused interface bandwidth based on an assigned weight of each of the weighted constituents of the interface.

Method and apparatus for shared shaping

Quality of Service (&ldquo;QoS&rdquo;) variables for predetermined protocol Type data units are stored in a cache memory. For data units that are associated with a flow, thirteen bytes selected out of the Internet Protocol (&ldquo;IP&rdquo;) header are employed as at least a portion of a key to perform a cache lookup to obtain at least one Quality of Service variable from the cache. Both routing and QoS information may be stored in the cache for retrieval upon a single lookup operation.

Quality of service control mechanism and apparatus

A clock crossing FIFO capable of functioning regardless of relative clock frequencies on the write and read sides. Toggle signals are utilized to cross the clock boundaries. The number of write counts which have been accrued but not acknowledged by the read side are tracked, and this number is stored as of the issuance of a write toggle. Upon toggle receipt on the read side, this number is latched as a measure of the number of data units which can be read from the FIFO. At the same time, the toggle is returned to the write side for decrementing the number of write counts outstanding by the number conveyed to the read side. Similar circuitry is employed for conveying to the write side circuitry the number of data units which have been read by the read side circuitry. The presently disclosed FIFO and associated circuitry operates independent of relative clock speeds, and the particular size of the FIFO is scalable.

Frequency independent asynchronous clock crossing FIFO

Growing community of inventors

Townsend, MA, United States of America

Paul J Giacobbe