摘要 |
<p>The IP filter (12), embodying the present invention, is a communications device designed to provide public network (14) or Internet (16) access to nodes (18) of private networks (10), advantageously without requiring the private nodes on such networks to register public Internet addresses. The IP filter presents a single IP address to the Internet and uses a plurality of IP ports to solve the problem of IP address conservation. It initiates sessions by assigning private side IP sessions to a unique port of the IP filter's public address. The IP filter effects a translation between a source port number for the private network and a destination port number for the public network for communication therebetween. Benefits of the IP filter include private node security and conservation of Internet-registered addresses.</p> |