Patent ID: 8910267

Claim:
A method for managing connections in a firewall, the method comprising the steps of: receiving packets from an external network; generating a connection table containing the following information: information about packets included by a connection (an original packet, a reply packet, ICMP errors); information about transformations of a packet in the case of address translation; a network protocol type; a connection state (new, established, closed); a timestamp of processing of the last packet; information about groups of connections in the case of application layer protocols (FTP, SIP); determining the total number of currently established connections; determining a level of firewall load by comparing the number of established connections with a predetermined threshold; identifying new and established connections based on two-way exchange of packets between a client and a server; identifying closed connections based on processing ICMP error messages or flags in a TCP header (for TCP only); dynamically determining current timeout values for connections from the following parameters: the network protocol type; the connection state; the firewall load level; modifying the last packet processing timestamp, if any packet is passed within a given connection or a group of connections; removing the connection, if the last packet processing timestamp differs from the current time by a value greater than the timeout determined for said connection.