Patent ID: 7831822
Filing Date: 2010-11-09
Classification: H04L

Abstract:
1. A stateful packet inspection apparatus comprising: a processor and a memory, the memory having stored thereon: a session table that stores session data of a packet received from an external network; a hash key generator that hashes a parameter extracted from the received packet and generates a hash pointer of the session table corresponding to the packet, wherein each session entry of the table includes a position change flag so that one of a source and destination addresses, which has a lower value, always precedes the other with the higher value; a session detection module used to search the session table for a session corresponding to the received packet; a session management module that performs management of the session table, the management including addition, deletion, and change of sessions of the session table; and a packet inspection module that generates state information corresponding to the received packet from both directionality information of the packet and entry header information of the packet stored in the session table and then inspects the packet based on the generated state information.