Media access control (MAC) address hardware learning method and system based on hash table and ternary content addressable memory (TCAM) table

Abstract

The invention discloses a media access control (MAC) address hardware learning method and system based on a hash table and a ternary content addressable memory (TCAM) table, and relates to the MAC address learning field. According to the MAC address hardware learning method and system, when no MAC address conflict happens, the hash table is used for storing learned MAC addresses, and a static random access memory (SRAM) or a dynamic random access memory (DRAM) is applied to the hardware of the hash table; and when MAC address conflict happens, the TCAM table is used for caching conflicted MAC addresses, a TCAM storage is applied to the hardware of the TCAM, idle table items can be positioned through one-time searching due to the fact that parallel seeking is performed on the hardware of the TCAM, and the number of the table items of the TCAM is the number of the conflicted MAC addressed which can be practically cached. The MAC address hardware learning method is achieved on a general programmable exchange chip, does not need support of hardware circuits, is high in learning efficiency and small in occupied internal memory resources, is flexible in application due to the fact that the general algorithm is adopted, and can achieve complete control on conflict probability.

Description

technical field [0001] The present invention relates to the field of MAC (Media Access Control, media access control) address learning, in particular to a MAC address hardware learning based on HASH (hash) table and TCAM (Ternary Content Addressable Memory, ternary content addressable memory) table methods and systems. Background technique [0002] With the development of economic globalization, more and more enterprises are expanding their distribution areas, and there is an urgent need for telecom operators to provide link connections in order to include all branches of enterprises to form a private network within the enterprise. Under such market demands, VPLS (Virtual Private Lan Service, Virtual Private LAN Service) technology emerged as the times require. VPLS technology combines the advantages of Ethernet technology and MPLS (Multi-Protocol Label Switching, Multi-Protocol Label Switching) technology, through The IP (Internet Protocol, Internet Protocol) / MPLS network ...

AI Technical Summary

Problems solved by technology

[0014] The multi-bucket cache conflict method largely solves the problem that a single hash bucket cannot cache MAC addresses with the same discrete value, and the utilization efficiency of hardware resources is also relatively high. However, this method requires a large number of conflict buckets to work together and requires a dedicated The support of hardware circuits, and the search method of free entries in each conflict bucket requires a dedicated hardware circuit to implement the search algorithm, because the algorithm it implements is not public, so the application is not flexible; in addition, because this method only uses the current conflict The free entry resources in the bucket are used to cache conflicts. Therefore, only up to 8 MAC addresses with the same discrete value can be cached, and the ability to cache conflicts is limited for more severe situations with the same discrete value.

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