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:
Mar. 11, 2003
Filed:
Oct. 19, 1999
Yasuhiko Matsunaga, Tokyo, JP;
Morihisa Momona, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A multicast communication apparatus includes a center station and subscriber stations. Each station includes input/output ports, and a section for layer- bridging between the ports in a 7-layer OSI model. Each station includes a transfer control table for holding group addresses, and an address converting section. Each section also includes a section for transferring a multicast packet to corresponding ports, a section for analyzing the layer- message received from each port, a section for checking registration of layer- group addresses corresponding to subscription requests, transferring or not transferring the messages depending on whether the group addresses are registered, registering the corresponding group addresses, a section for transferring subscription state query messages and generating/outputting layer- multicast subscription request messages destined to acquired layer- group addresses, and a section for deleting a layer- group address from the table if the corresponding multicast subscription request message is not received for a predetermined period of time, and deleting a layer- group address if the corresponding layer- group address is not present. A multicast communication method is also disclosed.