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. 15, 2020
Filed:
Mar. 21, 2018
Barefoot Networks, Inc., Santa Clara, CA (US);
Milad Sharif, Los Altos, CA (US);
Barefoot Networks, Inc., Santa Clara, CA (US);
Abstract
Some embodiments provide a method for configuring unit memories (e.g., unit static random access memories (SRAMs) and ternary content addressable memories (TCAMs) of a network forwarding IC to implement a set of longest prefix matching (LPM) tables. Two different methods of providing a longest prefix match (LPM) operation that minimize the use of ternary content addressable memory (TCAM) are presented. Each method takes advantage of the use of match-action stages and the programmability of the unit memories. An algorithmic LPM embodiment is presented which uses a TCAM index with pointers to SRAM partitions that store subtrees of a routing tree (routing trie structure) and performs subtree rearrangements in the partitions upon the addition of certain routing entries. A chained LPM embodiment, allocates separate exact-match tables for a set of address prefix lengths in, for example, SRAMS, as well as a set of non-exact match tables in, for example, TCAMs.