Method and apparatus for implementing hunt group support for a crosspoint ...

(54) METHOD AND APPARATUS FOR

IMPLEMENTING HUNT GROUP SUPPORT
FOR A CROSSPOINT CONTROLLER

(75) Inventors: Jeffrey J. Nelson, Louisville; James P.

Fugere, Boulder; Ken N. Jessop,

Arvada, all of CO (US)

(73) Assignee: McData Corporation, Broomfield, CO (US)

( * ) Notice: Under 35 U.S.C. 154(b), the term of this patent shall be extended for 0 days.

(21) Appl. No.: 08/942,506

(22) Filed: Oct. 2, 1997

(51) Int. CI. II04I. 12 50

(52) U.S. CI 370/380

(58) Field of Search 370/351, 357,

370/359, 362, 366, 370, 380, 427; 340/825.79, 825.83; 379/272, 273, 274

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OTHER PUBLICATIONS

McDATA Corporation, Information is the Lifeblood of Your

Success. Fibre Channel Switching Is the Pulse, 1997'.

McDATA Corporation, LinkMaster 9191 ESCON Multiport

Repeater, 1993, 1994.

IBM, ESCON Director Model 3, 1994.

Fibre Channel Association, Fibre Channel Quick Reference

Card, 1997.

IBM, ESCON Director Model 4 (9033) for ESCON Architecture, 1995.

* cited by examiner

Primary Examiner—Chau Nguyen

Assistant Examiner—Enrique L Santiago

(74) Attorney, Agent, or Firm—Richard A. Bachand

(57) ABSTRACT

A method and apparatus which obviates the throughput limitations retries generated by busy conditions of conventional switches which are limited to but a single path between any two ports through the use of a "hunt group" concept whereby multiple paths can be provided between a participating group member and another port. These multiple paths may be associated in groups of, for example, eight, with each grouping of eight paths then comprising a "hunt group" whereby the first available member of the hunt group will be selected to enable the connection should the first be "busy". The particular embodiment disclosed comprises a plurality of sequentially organized hunt groups starting on a boundary of eight associated with ports 0-7, 8-15, . . . through 248-255.

27 Claims, 9 Drawing Sheets