Backplane interface adapter with error control and redundant fabric

• US 7,948,872 B2
• Filed: 03/09/2009
• Issued: 05/24/2011
• Est. Priority Date: 11/17/2000
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Foundry Networks LLC (Broadcom, Inc.)
• Inventors: Chang, Andrew, Patel, Ronak, Wong, Ming G., Wong, Yuen Fai, Lin, Yu-Mei
• Primary Examiner(s): Pham; Chi H.
• Assistant Examiner(s): MEW, KEVIN D
• Application Number:
  US12/400,645
• Publication Number:
  US 20090290499A1
• Time in Patent Office: 806 Days
• Field of Search: 370230-232, 370235-236, 370358-360, 370362-367, 370/380, 370386-389, 370/392, 370/396, 370401-402, 370/412, 370419-422, 370428-429, 370/463, 370/503, 370507-514, 370217-220, 370/225
• US Class Current: 370/217
• CPC Class Codes: H04L 45/74 Address processing for routing
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/6225 Fixed service order, e.g. Round Robin
• CPC Class Codes: H04L 49/153 ATM switching fabrics having parallel switch planes
• CPC Class Codes: H04L 49/1538 Cell slicing
• CPC Class Codes: H04L 49/25 Routing or path finding in a switch fabric
• CPC Class Codes: H04L 49/30 Peripheral units, e.g. input or output ports
• CPC Class Codes: H04L 49/3063 Pipelined operation
• CPC Class Codes: H04L 49/352 Gigabit ethernet switching [GBPS]
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers

Abstract

A backplane interface adapter with error control and redundant fabric for a high-performance network switch. The error control may be provided by an administrative module that includes a level monitor, a stripe synchronization error detector, a flow controller, and a control character presence tracker. The redundant fabric transceiver of the backplane interface adapter improves the adapter'"'"'s ability to properly and consistently receive narrow input cells carrying packets of data and output wide striped cells to a switching fabric.

Claims

1. A system, comprising:

a first switching blade and a second switching blade, each switching blade having a plurality of cross points for receiving serial data streams; and

at least one blade coupled to each switching blade through a backplane connection, wherein said at least one blade includes a backplane interface adapter and a plurality of redundant fabric transceivers which can switch forwarding of traffic between the first switching blade and the second switching blade from the backplane interface adapter;

wherein the backplane interface adapter enables and disables transmitting packets and the redundant fabric transceiver is configured to switch forwarding of traffic received by the redundant fabric transceiver from a first switching blade to a second switching blade.

2. A system comprising:

a first switching fabric;

a second switching fabric; and

one or more blades, each blade including at least one backplane interface adapter and at least one redundant fabric transceiver, wherein each blade is configured to switch from using a first switch fabric to using a second switch fabric instead of the first switching fabric without dropping packets;

wherein the backplane interface adapter enables and disables transmitting packets and the redundant fabric transceiver designates a switching fabric for receiving packets.

3. The system of claim 2 wherein the first switching fabric and the second switching fabric are each configured to receive packets from the one or more blades and forward the received packet to the one or more blades.

4. The system of claim 2 wherein:

the backplane interface adapter, when enabled to receive and transmit packets, allows packets to pass through to the redundant fabric transceiver and onto a designated switching fabric,

the backplane interface adapter, when disabled to receive and transmit packets, stops packets from passing to the redundant fabric transceiver and transfers packets stored in the redundant fabric transceiver to the designated switching fabric; and

the redundant fabric transceiver is operable to change the designated switching fabric from the previously designated switching fabric to another switching fabric.

5. A system comprising:

one or more blades, each blade including at least one backplane interface adapter and at least one redundant fabric transceiver, wherein each blade is configured to switch from using a first switch fabric to using a second switch fabric instead of the first switching fabric without dropping packets;

wherein the redundant fabric transceiver is configured to;

disable the back plane interface adapter from forwarding packets for a predetermined time period that is sufficient to transfer the packets stored in the redundant fabric transceiver to the first switching fabric; and

designate a second switching fabric when a switch-over-timer indicates a lapse in time equal to the predetermined time period.

6. The system of claim 5 wherein the redundant fabric transceiver comprises a buffer for storing packets.

7. A method comprising:

receiving packets at a backplane interface adapter;

forwarding the received packets to a first designated switching fabric;

changing from the first designated switching fabric to a second switching fabric without dropping packets;

wherein the changing comprises;

disabling the backplane interface adapter from forwarding packets;

after disabling, for a predetermined time period, forwarding, to the first designated switching fabric, packets stored in a redundant fabric transceiver buffer associated with the backplane interface adapter after the backplane interface adapter is disabled;

after the predetermined time period has lapsed, designating the second switching fabric for receiving packets from the redundant fabric transceiver buffer; and

enabling the backplane interface adapter to forward packets received by the backplane interface adapter to the second switching fabric instead of the first switching fabric using the redundant fabric transceiver.

8. The method of claim 7 further comprising:

sending new packets to the redundant fabric transceiver; and

forwarding the new packets from the redundant fabric transceiver to the second switching fabric without dropping any data in the packets.

9. The method of claim 7 wherein the backplane interface adapter is disabled by setting bits in a register disposed in the redundant fabric transceiver.

10. The method of claim 7 wherein disabling a backplane interface adapter throttles the backplane interface adapter and stops the backplane interface adapter from sending packets to the redundant fabric transceiver.

11. The method of claim 7 wherein the amount of time it takes to forward all packets stored in a redundant fabric transceiver buffer to the first switching fabric, after the backplane interface adapter is disabled, is predetermined.

12. The method of claim 7 wherein the second switching fabric is designated by setting the Fabric Active bits in a register disposed in the redundant fabric transceiver.

13. The method of claim 7 wherein the backplane interface adapter is enabled by clearing a bit in a register disposed in the backplane interface adapter.

14. The method of claim 7 further comprising forwarding to the first switching fabric all packets stored in a crosspoint buffer after the backplane interface adapter is disabled.