Openflow flow table look-up method and device

Abstract

The invention discloses an openflow flow table look-up method comprising the following steps: on a control plane, dividing openflow flow tables at various levels into an exact matching flow table and at least one classification matching flow table according to the key field, and issuing flow table configuration information as a table entry to the exact matching flow table or the at least one classification matching flow table according to the key field of the flow table configuration information; on a forwarding plane, looking up in the exact matching flow table by use of all the keywords of a message, and when a matching table entry is found, processing the message according to the function of the table entry; when no matching table entry is found, extracting the keywords of different key fields of the message to look up in the at least one classification matching flow table in parallel, dynamically establishing a table entry of the exact matching flow table according to the result of table look-up, and processing the message according to the function of the table entry. The invention further discloses an openflow flow table look-up device.

Description

technical field [0001] The invention relates to the field of Ethernet data communication, in particular to a table look-up method and device for an openflow flow table. Background technique [0002] With the rise of Software Defined Network (SDN, Software Defined Network), openflow, as one of the mainstream technologies, has been extensively researched, and the standards are becoming more mature, and are gradually accepted and recognized by various equipment manufacturers and operators. However, as an emerging technology, openflow technology has also encountered huge challenges in both forwarding and control levels, and there are many technical bottlenecks in its implementation, which hinder the further promotion and application of openflow technology. [0003] From the perspective of forwarding, there are mainly the following problems: [0004] 1. In order to cover more complex business and business expansion needs, openflow technology proposes the concept of multi-level f...

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Problems solved by technology

[0004] 1. In order to cover more complex business and business expansion needs, openflow technology proposes the concept of multi-level flow table, which does not limit the number of levels of flow table. Each message may use different keywords to search the flow table multiple times. It is also possible to use the search result of the upper-level flow table as a keyword to search for the subsequent flow table, which brings about the complexity of the design and the problem of reducing forwarding performance

[0005] 2. The OpenFlow standard defines a flow table that can use any combination of keyword fields to look up the table. The current mainstream method is to use a three-state content addressable memory (TCAM) chip to implement the flow table, and the keyword defined in the openflow standard There are many fields. If all keywords are considered, a key of 576 bits is required to represent an entry. Then a 36Mbit TCAM chip can only store a maximum of 64K entries. This specification is difficult to meet the needs of the industry. , and the TCAM chip is an expensive resource, it is not realistic to implement the flow table purely through the TCAM chip

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