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

Abstract

Disclosed in the present invention are a MAC address hardware learning method and system based on a hash table and a TCAM table, relating to the field of MAC address learning. When there is no MAC address conflict, a learnt MAC address is stored in the hash table by means of SRAM or DRAM on hash table hardware; when there is a MAC address conflict, the conflicting MAC address is cached in the TCAM table by means of a TCAM memory on TCAM hardware. Because a parallel search is performed on the TCAM hardware, idle entries can be located by a single search; and the number of the entries of the TCAM is the actual number of conflicting MAC addresses capable of being cached. The present invention can be implemented on a general programmable exchange chip, does not need the support of a dedicated hardware circuit, has a high learning rate, occupies few memory resources, is flexible in application by adopting a general algorithm, and can achieve complete controllability of the 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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