The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 20, 1999
Filed:
Jun. 11, 1997
J Bryan Lyles, Mountain View, CA (US);
Landis C Rogers, Kingston, NH (US);
Christopher J Kappler, Charlestown, MA (US);
Xerox Corporation, Stamford, CT (US);
Abstract
Rate shaping is provided in per-flow queued routing mechanisms for available bit rate service. A traffic shaper in a packet switched communications system serially emits packets of time multiplexed flows in substantial compliance with individual network traffic contracts for the respective flows. The individual network traffic contracts include contracts which specify respective peak packet emission rates and associated peak rate tolerances for certain of the flows and which cause each of the flows to fall into mutually exclusive categories. The traffic shaper includes a queuing mechanism and a scheduling mechanism. The queuing mechanism organizes pending packets of active flows, including the certain flows, in respective queues in accordance with an oldest pending packet at head of queue order. The scheduling mechanism is coupled to the queuing mechanism for scheduling the packets of the active flows for emission. The scheduling mechanism includes a relatively high priority non-work conserving calendar queue, at least one relatively low priority work conserving queue, and another non-working conserving calendar queue of indeterministic priority relative to the high and low priority queues. The scheduling mechanism can also include a control mechanism for monitoring emissions from the high and low priority queues and for selectively descheduling packets scheduled on the high and low priority queues.