System and method for mid-plane interconnect using switched technology

• US 6,675,254 B1
• Filed: 09/29/2000
• Issued: 01/06/2004
• Est. Priority Date: 09/29/2000
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Wachel, Robert D.
• Primary Examiner(s): Myers, Paul R.
• Assistant Examiner(s): PHAN, RAYMOND NGAN
• Application Number:
  US09/676,173
• Time in Patent Office: 1,194 Days
• Field of Search: 710/305-306, 710/316-317, 710/300-302, 709/201, 709/227, 709/229-230, 709/238-242
• US Class Current: 710/316
• CPC Class Codes: G06F 13/409 Mechanical coupling back panels H05K7/1438

Abstract

A system and method for transferring information at a fast rate between add-in cards in a rack mount system are described. In one embodiment, the invention allow all the add-in cards within the rack mount system to be interconnected. All the main cards within the rack mount system connect to a switch card using point-to-point differential copper pairs. All communication over these differential copper pairs use a messaging protocol that provides a messaging protocol destination address that is used to route the information to the intended destination main card. The messaging protocol may be the Ethernet protocol. In an alternative embodiment, data redundancy is provided by having two switch cards in the rack mount system. A particular main card transmits one set of information to the first switch card and a second set of information (that is identical to the first set of information) to the second switch card. The first switch card routes the first set of information to a particular one of the main card that is the intended destination and the second switch card routes the second set of information to the destination main card (i.e., the first switch card and the second switch card transfer the first set of information and the second set of information to the same destination main card). The destination main card uses the information that is first-to-arrive but if the information that is first-to-arrive has an error, then the later-to-arrive information is selected for use. The point-to-point differential copper pairs between the main cards and the one or more switch cards are referred to as a switched Ethernet interconnect. The switched Ethernet interconnect may be integrated within the mid-plane or using external cables.

Claims

1. A method for allowing a plurality of main cards within a rack mount system to communicate with each other, comprising:

transferring a first set of information from a first one of the plurality of main cards to a first switch card using a first one of a plurality of point-to-point links;

routing the first set of information, using the first switch card, to a second one of the plurality of main cards as specified by a messaging protocol destination address using a second one of the plurality of point-to-point links;

transferring a second set of information from the first one of the plurality of main cards to a second switch card using a third one of the plurality point-to-point links;

routing the second set of information, using the second switch card, to the second one of the plurality of main cards as specified by the messaging protocol destination address using a fourth one of the plurality of point-to-point links; and

selecting, using the second one of the plurality of main cards, at least one of the first set of information and the second set of information.

2. The method of claim 1, wherein the second set of information is a duplicate of the first set of information.

3. The method of claim 1, wherein the second one of the plurality of main cards selects for use the first to arrive between the first set of information and the second set of information.

4. The method of claim 1, wherein the second one of the plurality of main cards discards the set of information that is first-to-arrive and uses the set of information that is later-to-arrive if the set of information that is first-to-arrive has an error.

5. The method of claim 1, wherein the rack mount system complies with a CompactPCI Specification and each of the plurality of main cards, the first switch card, and the second switch card have a J3 connector, and the plurality of main cards, the first switch card, and the second switch card link to the plurality of point-to-point links using the J3 connector.

6. The method of claim 1, wherein the first set of information and the second set of information comply with a Ethernet protocol that includes the messaging protocol destination address.

7. The method of claim 1 wherein the plurality of point-to-point links are integrated within a mid-plane of the rack mount system.

8. The method of claim 1 wherein the plurality of point-to-point links are on external cables that interconnect the plurality of main cards and at least one of the first switch card and the second switch card.

9. The method of claim 1 wherein the plurality of point-to-point links are a plurality of differential copper pairs.

10. A system for allowing a plurality of main cards within a rack mount system to communicate with each other, comprising:

a first one of the plurality of main cards to transfer a first set of information to a first switch card using a first one of a plurality of point-to-point links;

the first switch card, also within the rack mount system, to route the first set of information to a second one of the plurality of main cards as specified by a messaging protocol destination address using a second one of the plurality of point-to-point links;

the first one of the plurality of main cards transfers a second set of information to a second switch card using a third one of the plurality of point-to-point links;

the second switch card routes the second set of information to the second one of the plurality of main cards as specified by the messaging protocol destination address; and

the second one of the plurality of main cards selects at least one of the first set of information and the second set of information.

11. The system of claim 10, wherein the second set of information is a duplicate of the first set of information.

12. The system of claim 10, wherein the second one of the plurality of main cards selects for use the first to arrive between the first set of information and the second set of information.

13. The system of claim 10, wherein the second one of the plurality of main cards discards the set of information that is first-to-arrive and uses the set of information that is later-to-arrive if the set of information that is first-to-arrive has an error.

14. The system of claim 10, wherein the rack mount system complies with a CompactPCI Specification and each of the plurality of main cards, the first switch card, and the second switch card have a J3 connector, and the plurality of main cards, the first switch card, and the second switch card link to the plurality of point-to-point links using the J3 connector.

15. The system of claim 10, wherein the first set of information and the second set of information comply with a Ethernet protocol that includes the messaging protocol destination address.

16. The system of claim 10 wherein the plurality of point-to-point links are integrated within a mid-plane of the rack mount system.

17. The system of claim 10 wherein the plurality of point-to-point links are on external cables that interconnect the plurality of main cards and at least one of the first switch card and the second switch card.

18. The system of claim 10 wherein the plurality of point-to-point links are a plurality of differential copper pairs.