Network device including central and distributed switch fabric subsystems

• US 7,039,046 B1
• Filed: 07/11/2000
• Issued: 05/02/2006
• Est. Priority Date: 05/20/2000
• Status: Expired due to Term

• Current Assignee: Ciena Corporation
• Original Assignee: Ciena Corporation
• Inventors: Simons, Corey, Branscomb, Brian, Bell, Colin, Noel, Chris R., Manor, Larry B., Everdell, Peter B.
• Primary Examiner(s): Vu, Huy D.
• Assistant Examiner(s): RYMAN, DANIEL J
• Application Number:
  US09/613,940
• Time in Patent Office: 2,121 Days
• Field of Search: 370/216, 370/360, 370/389, 370/351, 370438- 39, 370451- 52, 370257- 8
• US Class Current: 370/388
• CPC Class Codes: H04L 49/15 Interconnection of switching modules
• CPC Class Codes: H04L 49/254 Centralised controller, i.e. arbitration or scheduling

Abstract

The present invention reduces the cost of a minimally configured network device by providing a network device with a distributed switch fabric. Such a network device locates a portion of the switch fabric functionality on each forwarding card allowing the minimal network device configuration to include less than the entire switch fabric functionality. The cost of the minimal configuration is, therefore, reduced allowing network service providers to more quickly recover the initial cost of the network device. As new services are requested, additional functionality, including both forwarding cards and universal port cards may be added to the network device to handle the new requests, and the fees for the new services may be applied to the cost of the additional functionality. Consequently, the cost of the network device more closely tracks the service fees received by network providers.

Claims

1. A network device comprising:

at least one central switch fabric subsystem; and

at least one distributed switch fabric subsystem located on a forwarding card coupled to said central switch fabric subsystem and capable of transferring network data packets with said central switch fabric subsystem;

wherein said central switch fabric subsystem comprises;

a central controller subsystem located on a first switch fabric card; and

a central data transfer subsystem coupled with said central controller subsystem,

wherein a portion of said central data transfer subsystem is located on a second switch fabric card;

wherein said distributed switch fabric subsystem comprises;

a distributed fabric data transfer subsystem; and

a distributed controller subsystem coupled with said distributed data transfer subsystem for controlling network data transfer through the distributed data transfer subsystem.

2. The network device of claim 1, where another portion of the central data transfer subsystem is located on a third switch fabric card.

3. The network device of claim 1, wherein the distributed switch fabric subsystem further comprises:

a local timing subsystem coupled with the distributed data transfer subsystem and the distributed controller system.

4. The network device of claim 1, wherein the distributed switch fabric subsystem further comprises a data slice component.

5. The network device of claim 1, wherein the distributed controller subsystem comprises an enhanced port processor.

6. The network device of claim 1, wherein a distributed switch fabric subsystem interface is coupled with the distributed switch fabric subsystem and is capable of transferring network data with the distributed switch fabric subsystem.

7. The network device of claim 1, wherein the distributed switch fabric subsystem is a first distributed switch fabric subsystem and the network device further comprises:

a second distributed fabric subsystem coupled to the central switch fabric subsystem and capable of transferring network data with the central switch fabric subsystem and the first distributed fabric subsystem.

8. The network device of claim 7, wherein the central controller subsystem comprises a scheduler component.

9. The network device of claim 7, wherein the central data transfer subsystem comprises a cross-bar component.

10. The network device of claim 1, wherein:

said central controller subsystem couples with the distributed switch fabric subsystem; and

the central data transfer subsystem couples with the central controller subsystem and the distributed switch fabric subsystem for transferring network data with the distributed switch fabric subsystem.

11. The network device of claim 10, wherein the central switch fabric subsystem further comprises:

a local timing subsystem coupled with the central controller subsystem.

12. The network device of claim 10, wherein the central switch fabric subsystem further comprises:

a local timing subsystem coupled with the central data transfer subsystem.

13. The network device of claim 1, wherein the central switch fabric subsystem includes at least one local timing device subsystem and wherein the distributed switch fabric subsystem includes at least one local timing subsystem and the network device further comprises:

a central timing subsystem coupled to the at least one local timing device subsystem and the at least one local timing subsystem.

14. The network device of claim 13, wherein the central timing subsystem is located within the central switch fabric subsystem.

15. A network device, comprising:

a central switch fabric subsystem; and

a plurality of distributed switch fabric subsystems located on a forwarding card coupled to the central switch fabric subsystem, wherein each of the plurality of distributed switch fabric subsystems is capable of transferring network packet data with each of the plurality of distributed switch fabric subsystems through the central switch fabric subsystem and

wherein said central switch fabric subsystem comprises;

a central controller subsystem located on a first switch fabric card; and

a central data transfer subsystem coupled with said central controller subsystem, wherein a portion of said central data transfer subsystem is located on a second switch fabric card;

wherein at least one of said distributed switch fabric subsystem comprises;

a distributed data transfer subsystem comprising a data slice component, and

a distributed controller subsystem coupled with the distributed data transfer subsystem for controlling network data transfer through the distributed data transfer subsystem.

16. The network device of claim 15, wherein the central switch fabric subsystem is a first central switch fabric subsystem and the network device further comprises:

a second central switch fabric subsystem coupled with the plurality of distributed switch fabric subsystems, wherein each of the plurality of distributed switch fabric subsystems is capable of transferring network data with each of the plurality of distributed switch fabric subsystems through the second central switch fabric subsystems.

17. The network device of claim 16, wherein one of the first and second central switch fabric subsystems is a primary central switch fabric subsystem and the other of the first and second central switch fabric subsystems is a redundant central switch fabric subsystem.

18. The network device of claim 16, wherein certain ones of the plurality of distributed switch fabric subsystems are primary distributed switch fabric subsystems and certain others of the plurality of distributed switch fabric subsystems are redundant distributed switch fabric subsystems.

19. The network device of claim 18, wherein at least a portion of the plurality of distributed switch fabric subsystems provide a 1:

N redundancy scheme.

20. A network device, comprising:

a plurality of switch fabric cards comprising a central switch fabric subsystem;

a plurality of forwarding cards coupled with the switch fabric cards, each forwarding card comprising a switch fabric interface and a distributed switch fabric subsystem; and

at least one distributed switch fabric subsystem coupled to said central switch fabric subsystem and capable of transferring network data packets with said central switch fabric subsystem;

wherein said central switch fabric subsystem comprises;

a central controller subsystem located on a first switch fabric card; and

a central data transfer subsystem coupled with said central controller subsystem, wherein a portion of said central data transfer subsystem is located on a second switch fabric card;

wherein said at least one distributed switch fabric subsystem comprises;

a distributed data transfer subsystem; and

a distributed controller subsystem coupled with said distributed data transfer subsystem for controlling network data transfer through the distributed data transfer subsystem;

wherein each of the forwarding cards is capable of transmitting network packet data to another forward card through its switch fabric interface and via said central and distributed switch fabric subsystems.

21. The network device of claim 20, wherein the at least one distributed switch fabric subsystem comprises:

a data slice subsystem for transferring network data with the central switch fabric subsystem.

22. The network device of claim 21, wherein the data slice subsystem comprises:

a plurality of data slice components for transferring network data with the central switch fabric subsystem.

23. The network device of claim 22, wherein the at least one distributed switch fabric subsystem further comprises:

a data slice controller subsystem connected to the data slice subsystem for controlling which network data the data slice subsystem transfers.

24. The network device of claim 22, wherein the at least one distributed switch fabric subsystem further comprises:

a local timing subsystem coupled with the data slice controller subsystem and the data slice subsystem.

25. The network device of claim 20, wherein the switch fabric interface comprises a switch fabric interface component.

26. The network device of claim 20, wherein the central switch fabric subsystem comprises:

a scheduler coupled with the distributed switch fabric subsystem for scheduling network data transfers.

27. The network device of claim 20, wherein the central switch fabric subsystem includes at least one local timing device subsystem and wherein the distributed switch fabric subsystem includes at least one local timing subsystem and the network device further comprises:

a central timing subsystem coupled to the at least one local timing device subsystem and the at least one local timing subsystems.