Patent ID: 9049157
Filing Date: 2015-06-02
Classification: H04L

Abstract:
1. A Ternary Content Addressable Memory (TCAM)-based Longest Prefix Match (LPM) lookup table comprising: a TCAM, an associated Random Access Memory (RAM) and an additional RAM; the TCAM configured to store a TCAM entry referencing an LPM entry in the associated RAM and a TCAM entry corresponding to a common prefix of a plurality of LPM entries, wherein the plurality of LPM entries is selected by, in response to incremental changes in LPM entries, prioritizing based on the incremental changes candidate array entries corresponding to combination of LPM entries; the TCAM further configured to remove a plurality of TCAM entries each corresponding to one of said plurality of selected LPM entries other than said TCAM entry corresponding to said common prefix; the associated RAM configured to store a results entry corresponding to said stored TCAM entry and to overwrite results entries associate with each of said removed TCAM entries; and the additional RAM configured to store an array entry selected from the candidate array entries, the selected array entry corresponding to the combination of said plurality of selected LPM entries and including results entries corresponding to the overwritten results entries; wherein said LPM lookup table, after the TCAM removes the plurality of TCAM entries, still includes at least one TCAM entry referencing an LPM entry in the associated RAM.