Patent ID: 7694021

Claim:
A gateway network element that provides access to network elements that are not directly reachable, comprising: a processor that is directed by code; code that receives and sends packets over a first IP based interface to a first network; code that receives and sends packets over a second IP based interface to a second network, wherein IP addresses of network elements in the second network are not visible to network elements in the first network; code for categorizing the received packets based on the interface over which the packet was received, type of packet, and whether the destination address specifies the gateway network element; and code that selects and applies a set of filtering rules to the categorized packets based on a category of the received packet, wherein each set of said filtering rules differ from said other sets of filtering rules and comprises rules specifying which of said packets are accepted and which of said packets are rejected; wherein the first network is a Data Communications Network (DCN) and the second network is a Data Communication Channel (DCC) and the code that applies said filtering rules provides separation between the DCN network and the DCC network.