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:
Apr. 21, 2009
Filed:
Jan. 07, 2003
Eugene O'neill, Dublin, IE;
Kam Choi, Tring, GB;
Edele O'malley, Dublin, IE;
Maurice a Goodfellow, Dunstable, GB;
Eugene O'Neill, Dublin, IE;
Kam Choi, Tring, GB;
Edele O'Malley, Dublin, IE;
Maurice A Goodfellow, Dunstable, GB;
3Com Corporation, Marlborough, MA (US);
Abstract
A multi-port network unit for use in a cascade system of network units sends from a cascade port a packet including a special header having a source port ID, a destination port ID and a 'destination port known' field. The port IDs identify both a unit and a port within a unit. A routing database is set up, optionally by a discovery protocol, in terms of ports and either destination units (within the cascade) or source units (within the cascade). The database includes a mesh table, indicating from which cascade port a packet with a known destination port ID should be forwarded, without needing a fresh look-up. The database also includes a multicast exclusion table which allows ingress of packets with source unit IDs matched to an ingress port. The scheme allows a general mesh type of cascade while dynamically preventing closed loops.