The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 11, 2004
Filed:
May. 12, 2000
Zvika Bronstein, Ramat Efal, IL;
Opher Yaron, Tel Aviv, IL;
Golan Schzukin, Tel Aviv, IL;
Ilan Shimony, Haifa, IL;
3Com Corporation, Santa Clara, CA (US);
Abstract
A forwarding table comprising a combination of a hash table and a content addressable memory (CAM). The forwarding table combines a one way hash table and a small CAM to perform the forwarding information retrieval function. The CAM is used when an address cannot be found in the hash table. When MAC addresses are being added to the forwarding table, they are first tried in the hash table. The address is applied to the hash function and a resulting index input to the hash table. If a hit occurs, it indicates that an entry at that index already exists and a location in the CAM is then allocated for that address. As long as the CAM does not become full, a 100% hit rate is guaranteed. During retrieval, the hash table or the CAM forms the forwarding information output to the next processing stage. If an entry is not found in the hash table, it will typically be found in the CAM. If no entry is found in either, the received frame is flooded to all the ports of the network device.