Apparatus and method for routing traffic in multi-link switch

• US 20040071134A1
• Filed: 06/30/2003
• Published: 04/15/2004
• Est. Priority Date: 06/28/2002
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Brocade Communications Systems, Inc. (Broadcom, Inc.)
• Inventors: Vadivelu, Ramkumar
• Granted Patent: US 8,798,043 B2
• Time in Patent Office: Days
• US Class Current: 370/373
• CPC Class Codes: H04Q 2213/13141 Hunting for free outlet, circuit or channel
• CPC Class Codes: H04Q 2213/13146 Rerouting upon blocking/overload, rearrangement
• CPC Class Codes: H04Q 2213/13332 Broadband, CATV, dynamic bandwidth allocation
• CPC Class Codes: H04Q 2213/13352 Self-routing networks, real-time routing
• CPC Class Codes: H04Q 2213/13353 Routing table, map memory
• CPC Class Codes: H04Q 3/66 Traffic distributors

Abstract

A method of routing traffic in a switch includes forming an optimized routing table specifying for each switch ingress port an exit port to be utilized to reach a specified destination domain. The optimized routing table is formed in accordance with load distribution, oversubscription, and fragmentation criteria. The optimized routing table is distributed to a set of ingress ports of the switch. Traffic is processed at the set of ingress ports in accordance with the optimized routing table

Claims

1. A method of routing traffic in a switch, comprising:

forming a master routing resource table specifying an ingress port, a set of destination domains, a set of exit ports available to access said set of destination domains, and port capacity values corresponding to said set of exit ports;

applying optimization criteria to said master routing table to form an optimized routing table specifying a selected exit port for each destination domain including matching an ingress port to an exit port with a common bandwidth;

distributing said optimized routing table to said ingress port of said switch; and

processing traffic at said ingress port in accordance with said optimized routing table.

2. The method of claim 1 further comprising:

identifying an alteration in the status of a host or target connected to said switch; and

forming a revised master routing resource table in response to said identifying, wherein said revised master routing resource table is formed to establish exit port load balance in accordance with predetermined criteria.

3. The method of claim 2 wherein distributing includes distributing said optimized routing table to a plurality of ingress ports of said switch.

4. The method of claim 1 further comprising:

recognizing a change in network fabric topology in response to a switch coming on line or going off line; and

forming a next hop table in response to said recognizing.

5. The method of claim 1 wherein applying further includes applying optimization criteria to match an ingress port to a corresponding exit port that services a hop to a specified destination domain.

6. The method of claim 1 wherein applying further includes applying optimization criteria to minimize oversubscription of an exit port.

7. The method of claim 1 wherein applying further includes applying optimization criteria to minimize fragmentation of an exit port.

8. A method of routing traffic in a switch, comprising:

forming an optimized routing table specifying for each switch ingress port an exit port to be utilized to reach a specified destination domain, wherein said optimized routing table is formed in accordance with optimization criteria including load distribution, oversubscription, and fragmentation, and including matching an ingress port to an exit port with a common bandwidth;

distributing said optimized routing table to a set of ingress ports of said switch; and

processing traffic at said set of ingress ports in accordance with said optimized routing table.

9. The method of claim 8 further comprising:

identifying an alteration in the status of a host or target connected to said switch; and

forming a revised optimized routing table in response to said identifying.

10. The method of claim 8 further comprising:

recognizing a change in network fabric topology in response to a switch coming on line or going off line; and

forming a next hop table in response to said recognizing.

11. The method of claim 8 wherein forming includes applying optimization criteria to match an ingress port to a corresponding exit port that services a hop to a specified destination domain.

12. The method of claim 8 wherein forming includes applying optimization criteria to minimize oversubscription of an exit port.

13. The method of claim 8 wherein forming includes applying optimization criteria to

minimize fragmentation of an exit port.

14. A computer readable medium to direct a computer to function in a specified manner, comprising:

an optimized routing table generator to produce an optimized routing table specifying for each switch ingress port an exit port to be utilized to reach a specified destination domain, wherein said optimized routing table generator incorporates optimization criteria including load distribution, oversubscription, and fragmentation, in forming said optimized routing table and including matching an ingress port to an exit port with a common bandwidth; and

a routing table distribution module to distribute said optimized routing table to a set of ingress ports of said switch.

16. The computer readable medium of claim 14 further comprising:

a host/target status change identifier to identify an alteration in the status of a host or target connected to said switch.

17. The computer readable medium of claim 14 further comprising:

a fabric change identifier to recognize a change in network fabric topology in response to a networked switch coming on line or going off line.

18. The computer readable medium of claim 14 wherein said optimized routing table generator applies optimization criteria to match an ingress port to a corresponding exit port that services a hop to a specified destination domain.

19. The computer readable medium of claim 14 wherein said optimized routing table generator applies optimization criteria to minimize oversubscription of an exit port.

20. The computer readable medium of claim 14 wherein said optimized routing table applies optimization criteria to minimize fragmentation of an exit port.