Backplane Interface Adapter with Error Control and Redundant Fabric

• US 20090287952A1
• Filed: 03/09/2009
• Published: 11/19/2009
• Est. Priority Date: 11/17/2000
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Foundry Networks Incorporated (Broadcom, Inc.)
• Inventors: Chang, Andrew Z., Patel, Ronak, Wong, Ming G., Lin, Yu-mei, Wong, Yuen Fai A.
• Granted Patent: US 7,995,580 B2
• Time in Patent Office: Days
• US Class Current: 714/2
• 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. An administrative module for use in a digital switch, wherein the digital switch includes a plurality of blades coupled to a switching fabric, and wherein each blade outputs serial data streams with in-band control information in multiple stripes to said switching fabric, said administrative module comprising:

a level monitor that monitors the data received at a receiving blade; and

a stripe synchronization error detector that detects a stripe synchronization error based on the amount of data monitored by said level monitor.

2. The administrative module of claim 1, wherein the data received at a receiving blade is sorted based on stripe and source information and stored in a set of data structures, and wherein:

said level monitor monitors the levels of data stored in each data structure receiving blade, and

said stripe synchronization error detector detects at least one of an overflow and underflow condition in the amount of data received on a respective stripe from a particular source.

3. The administrative module of claim 1, further comprising:

a flow controller that initiates a recovery routine to re-synchronize data across the stripes in response to detection of a stripe synchronization error.

4. The administrative module of claim 3, wherein said recovery routine includes throttling back the data flowing to one or more of said stripes.

5. The administrative module of claim 1, further comprising:

a control character presence tracker that identifies the presence of a K2 character during the recovery routine.

6. The administrative module of claim 1, wherein said stripe synchronization error detector detects a stripe synchronization error in response to any one or more of the following error conditions:

an incoming link error, a cross-point failure, and an outgoing link error.

7. A method for detecting stripe synchronization error in a network switch, comprising:

(a) sorting data received at a receiving slot based on stripe and source information;

(b) storing the sorted data in a set of data structures;

(c) monitoring the levels of data stored in each data structure; and

(d) detecting at least one of an overflow and underflow condition in the amount of data received on a respective stripe from a particular source.

8. The method of claim 7, wherein the source information identifies a slot that sent the data across a switching fabric of the network switch.

9. The method of claim 7, wherein the source information identifies a source packet processor that sent the data from a slot across a switching fabric of the network switch.

10. (canceled)

11. A method for managing out-of-synchronization traffic flow through a cross-point switch in a switching fabric, comprising:

(a) monitoring the level of stripe receive synchronization queues;

(b) determining whether an out-of-synchronization condition exists; and

(c) initiating a re-synchronization routine when said out-of-synchronization condition exists.

12-24. -24. (canceled)