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:
Jan. 29, 2002
Filed:
May. 12, 2000
Zvika Bronstein, Ramat Efal, IL;
Gennady Dosovitsky, Rishon Letzion, IL;
Opher Yaron, Tel Aviv, IL;
Golan Schzukin, Tel Aviv, IL;
Ilan Shimony, Haifa, IL;
3Com Corporation, Santa Clara, CA (US);
Abstract
An apparatus for and a method of compressing the forwarding decision for a frame within a network device. A forwarding decision is compressed yielding a forwarding pointer that occupies far less memory space than the corresponding output port vector. The compressed forwarding pointers are stored in a forwarding table that is accessed using a hash function. A forwarding CAM is used to resolve conflicts in the hash table. The output port vectors are stored in an output port vector table that comprises a relatively small number of possible combinations of the port vector. A forwarding decision is made for each received frame by a forwarding processor in the device. The forwarding decision is represented by a compressed forwarding pointer that is stored in a table and associated with the received frame. At some later point in time, the frame is output to one or more destination ports in accordance with a corresponding output port vector. At this time, the compressed forwarding decision is expanded to an output port vector using the relatively small port vector table. In this fashion, large memories to store the actual output port vector are not needed since only a relatively short pointer to the port vector is stored rather than the port vector itself.