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. 10, 2002
Filed:
May. 07, 1998
George Varghese, St. Louis, MO (US);
Srinivasan Venkatachary, St. Louis, MO (US);
Washington University, St. Louis, MO (US);
Abstract
A new process called “crossproducting” allows level 4 switching to be performed at gigabit speeds. In crossproducting, a database of routing filters or rules is “sliced” into columns corresponding to fields. Each column represents a set of prefixes or ranges. Given a data packet P, a best matching prefix or narrowest enclosing range lookup is performed separately for each packet field. The results of the lookups on individual fields are concatenated to quickly determine the earliest matching rule. The search can be optimized further through such techniques as removing default entries, creating multiple crossproduct tables, caching crossproducts, and early stopping, the latter optimization being made possible by recognizing that it is not necessary in all cases to search all columns for a match. The inventive devices and methods are applicable to various types of networks, including, but not limited to, the Internet and related types of networks, and telephone switching networks.