Patent ID: 6701432
Filing Date: 2004-03-02
Classification: H04L

Abstract:
A gateway for screening packets transferred over a network, the gateway including a plurality of network interfaces, each receiving and forwarding messages from a network through the gateway, a memory for temporarily storing packets received from a network, and a memory controller coupled to each of the network interfaces and configured to coordinate the transfer of received packets to and from the memory, the gateway including:a memory bus for transferring the received packets to and from the memory, the memory bus providing a first path for retrieving packets from the memory including a first portion of a rule set, where one or more oft accessed rule sets are stored; a firewall engine coupled to the memory bus, the firewall engine operable to retrieve packets from the memory and screen each packet prior to forwarding a given packet through the gateway and out an appropriate network interface; a local bus coupled between the firewall engine and the memory providing a second separate non-overlapping path for retrieving packets to and from the memory; and an expandable external rule memory configured to store lesser accessed rule sets and coupled to the local bus, the external rule memory including a second portion of the rule set accessible by the firewall engine using the local bus, wherein the firewall engine is operable to retrieve rules from the second portion of the rule set and screen packets in accordance with the retrieved rules.