Patent ID: 7480300
Filing Date: 2009-01-20
Classification: G06F,H04L

Abstract:
1. A method of operating a content addressable memory in the examination of a selected portion of a packet for conformity with at least one rule, comprising: (a) storing the rule in a first segment of a data line of the content addressable memory; (b) storing in a second segment of said data line a port bit mask identifying to which network unit ports said one rule is applicable; (c) identifying at least one particular port; and (d1) applying to the content addressable memory a word which comprises said selected portion in respect of said first segment; and in respect of said second segment a search bit pattern that selects said at least one port and masks other ports; and (d2) applying to said content addressable memory a comparison mask which excludes all said other ports from a comparison of the word with the contents of the content addressable memory.