At&t Intellectual Property I, LP

David Johnson

Robert Duncan Doverspike

Jennifer Lynn Rexford

Dahai Xu

Martin Suchara

Jia Wang

David Lee Applegate

Howard Karloff

Katrina Ligett

Gruia Calinescu

A resilient load balancing method uses fixed paths and a fixed path-splitting strategy to enable ingress routers to efficiently reroute traffic after a failure. An off-line management system computes a set of fixed paths and a set of splitting ratios for routing demand from ingress routers to egress routers, with sufficient capacity to meet demands under each failure scenario. That data is then used by the ingress router to reroute demand after observing a failure.

Method of simple and efficient failure resilient load balancing

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.

Compressing rectilinear pictures and minimizing access control lists

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Madison, NJ, United States of America

David Johnson