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:
Jun. 07, 2011
Filed:
Jun. 28, 2007
David L. Applegate, Maplewood, NJ (US);
Gruia Calinescu, Wilmette, IL (US);
David S. Johnson, Madison, NJ (US);
Howard Karloff, New York, NY (US);
Katrina Ligett, Pittsburgh, PA (US);
Jia Wang, Randolph, NJ (US);
David L. Applegate, Maplewood, NJ (US);
Gruia Calinescu, Wilmette, IL (US);
David S. Johnson, Madison, NJ (US);
Howard Karloff, New York, NY (US);
Katrina Ligett, Pittsburgh, PA (US);
Jia Wang, Randolph, NJ (US);
AT&T Intellectual Property II, LP, Atlanta, GA (US);
Abstract
A geometric model is considered for the problem of minimizing access control lists (ACLs) in network routers. A colored rectilinear pattern is created within an initially white rectangular canvas, and the basic operation is to choose a subrectangle and paint it a single color, overwriting all previous colors in the rectangle. The method operates on rectangular rule lists (RRLs) and access control lists (ACLs) in which all rectangles are strips that extend either the full length or the full height of the canvas. A polynomial-time algorithm optimally constructs such patterns when, as in the ACL application, the only colors are black and white (permit or deny). That algorithm is complemented by a significantly faster approximation algorithm that is guaranteed to be no worse than 3/2 optimal.