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:
Oct. 28, 2008
Filed:
Sep. 08, 2004
Tetsuo Imai, Tokyo, JP;
Tetsuo Imai, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
Apparatus for designing a virtual VLAN network includes a database representing a plurality of VLAN networks in a spanning tree topology, each of the networks being formed of a plurality of VLAN member nodes interconnected by links. In response to a network configuration request from a communications network, control circuitry determines the costs of the links, and then determines the least cost unicast paths by using a shortest path algorithm. A search is made through the least cost unicast paths for detecting a loop. If at least one loop is detected, a link of highest cost of the loop is blocked. All unicast paths of the blocked link are reestablished through links that circumvent the blocked link. A spanning tree built up with all the links accommodating the least cost unicast paths is established. Configuration command is sent to the network for configuring it according to the established spanning tree.