Event-driven flow control for a very high-speed switching node

(54) EVENT-DRIVEN FLOW CONTROL FOR A VERY HIGH-SPEED SWITCHING NODE

(75) Inventors: Rene Gallezot, Vence (FR); Rene

Glaise, Nice (FR); Francois Le Maut,

Nice (FR)

(73) Assignee: International Business Machines Corporation, Armonk, NY (US)

( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 347 days.

This patent is subject to a terminal disclaimer.

(21) Appl.No.: 11/856,508

(22) Filed: Sep. 17, 2007

(65) Prior Publication Data

US 2008/0016510 Al Jan. 17, 2008

Related U.S. Application Data

(63) Continuation of application No. 10/673,595, filed on Sep. 29, 2003, now Pat. No. 7,324,460.

(30) Foreign Application Priority Data

Nov. 28, 2002 (EP) 02368130

(51) Int. CI.

H04L1/00 (2006.01)

(52) U.S. CI 370/252; 370/235

(58) Field of Classification Search 370/252,

370/253, 235, 229, 412, 231, 230, 230.1, 370/232,389; 709/223-226; 718/104 See application file for complete search history.

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* cited by examiner

Primary Examiner—Ricky Ngo
Assistant Examiner—Gary Mui

(7'4) Attorney, Agent, or Firm—JoscelynG. Cockburn; Mark E. McBurney

(57) ABSTRACT

A method for controlling the flows of data packets that are switched or routed at nodes of high-speed communication networks is disclosed. According to the invention, resource metering units are assigned to resources shared between devices of the switch or router e.g., shared memories or link bandwidths. When the occupancy of a shared resource reaches a predetermined threshold, an event is generated and transmitted to devices sharing this resource. Furthermore, a periodic refresh of the overall flow control information is performed so that lost events are, however, eventually acted on. Thus, a new device may become active without perturbing the active flows after having gathered enough flow control information.

20 Claims, 6 Drawing Sheets