Apparatus and method for table search with centralized memory pool in a network switch

Patent metadata

Field	Value
Publication number	US-9264357-B2
Application number	US-201414201692-A
Country	US
Kind code	B2
Filing date	Mar 7, 2014
Priority date	Apr 30, 2013
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

A network switch includes packet processing units in a first processor core. An interface module is connected to the packet processing units. The interface module supports a unified table search request interface and a unified table search response interface. A common memory pool is connected to the interface module. The common memory pool includes a variety of memory types configurable to support multiple parallel table search requests.

First claim

What is claimed is:

1. A network switch, comprising;
a plurality of packet processing units in a first processor core;
an interface module connected to the plurality of packet processing units, the interface module supporting a unified table search request interface and a unified table search response interface, wherein the interface module includes individual engines with logic to coordinate different table search requests and an interface unit configured in accordance with a configuration table; and
a common memory pool connected to the interface module, the common memory pool including a variety of memory types configurable to support a plurality of parallel table search requests.

2. The network switch of claim 1 further comprising a second plurality of packet processing units in a second processor core connected to the interface module.

3. The network switch of claim 1 wherein the interface module is configured to support different types of table searches with different sized search keys.

4. The network switch of claim 1 wherein the variety of memory types includes Static Random Access Memory and Ternary Content Addressable Memory.

5. The network switch of claim 1 wherein the engines include a Longest Prefix Match engine, a hash search engine, a direct memory search engine and a Ternary Content Addressable Memory (TCAM) engine.

6. The network switch of claim 1 wherein the configuration table includes a plurality of columns and rows, each row specifying a search profile and each column specifying a search command for the search profile.

7. The network switch of claim 1 wherein the configuration table includes a table identification field operative as an index into a row of the configuration table.

8. The network switch of claim 1 wherein the configuration table includes a key byte mask field to specify the construction of a search key.

9. The network switch of claim 1 wherein the configuration table includes Longest Prefix Match search parameters.

10. The network switch of claim 1 wherein the configuration table includes logical communication lane parameters.

11. The network switch of claim wherein the configuration table includes a quality of service parameter.

12. The network switch of claim 1 wherein the configuration table includes a table entry eviction parameter.

13. The network switch of claim 1 wherein the interface module processes a table search request which is processed in accordance with parameters of the configuration table.

14. The network switch of claim 13 wherein the table search request includes a search key section and a control data section.

15. The network switch of claim 14 wherein the search key section includes parameters selected from a key size, hash function configuration and memory tile configuration.

16. The network switch of claim 14 wherein the control data section includes parameters selected from data size and data memory tile configuration.

17. The network switch of claim 1 wherein the common memory pool includes a plurality of Ternary Content Addressable Memory (TCAM) resources divided into addressable database segments.

18. The network switch of claim 17 wherein output from the TCAM resources is processed by an encoder to access Static Random Access Memory information corresponding to a TCAM hit.

19. The network switch of claim 1 wherein the common memory pool is alternately configurable for different numbers of tables and different search types.

20. The network switch of claim 1 wherein the common memory pool is alternately configurable for large capacity long latency tables and small capacity short latency tables.

Assignees

• Xpliant Inc

Inventors

• Wang Weihuang
• Daniel Tsahi
• Balan Mohan
• Siva Nimalan

Classifications

• H04L45/745 Primary

  Address table lookup; Address filtering · CPC title

• H04L45/74591 Primary

  using content-addressable memories [CAM] · CPC title

• H04L49/103

  using a shared central buffer; using a shared memory · CPC title

• H04L49/252

  Store and forward routing · CPC title

• H04L45/748

  using longest matching prefix · CPC title