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:
Sep. 25, 2007
Filed:
Jul. 16, 2002
Raphael J Weyman, Hemel Hempstead, GB;
Francisco Aquino, Marlborough, MA (US);
David Reinauer, Nashua, NH (US);
Jacek a Tulacz, Marlborough, MA (US);
Jane a Riegel, Marlborough, MA (US);
Raphael J Weyman, Hemel Hempstead, GB;
Francisco Aquino, Marlborough, MA (US);
David Reinauer, Nashua, NH (US);
Jacek A Tulacz, Marlborough, MA (US);
Jane A Riegel, Marlborough, MA (US);
3Com Corporation, Marlborough, MA (US);
Abstract
A network unit comprises a multiplicity of ports for transmitting and receiving data packets, a bridging facility and a routing facility. The network unit has a multiplicity of mutually exclusive states which includes an initial state from which said network unit can transition to either a slave state; or a waiting state from which in the absence of receipt from elsewhere of a broadcast advertisement including an advertised address corresponding to an address of the unit, the unit transitions to a master routing state in which the routing facility is enabled and the unit broadcasts a corresponding advertisement including an address of the unit. The unit transitions from the waiting state, when it receives from elsewhere (i.e., another unit) such a broadcast advertisement, to a master bridging state in which the routing facility is disabled and the unit provides commands for disabling a routing facility of other similar units to which the network is connected. The states include a slave routing state, in which the routing facility is enabled, and a slave bridging state, in which the routing facility is disabled. In the slave states the advertisements are not broadcast and the unit responds to routing enabling and disabling commands from a unit in a master state. The scheme provides in conjunction with external connectivity resilience in the event of a cascade failure.