System and method for network address translation as an external service in the access server of a service provider

Abstract

A system and method provides network address translation as an external service for private networks. Give the fact that local office networks (i.e., stub networks) are typically assigned only one globally unique IP address (or a small set of addresses), the invention presents a novel service provider access server (e.g., router) which performs basic network address translation (NAT) and network address port translation (NAPT) for such networks. The system allows NAT and NAPT features to be removed from stub network routers, thereby significantly reducing the cost of Internet infrastructure to individual companies and organizations. NAT features on service provider's access servers provide the ability for multiple hosts in disparate private (unregistered) networks to utilize the services of a service provider, using a single global address for each private network and allow private networks to avoid renumbering with access to each new service provider.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates generally to computer network connections to the Internet and more particularly to a system and method for network address translation within an access server of a service provider.[0003]2. Related Art[0004]Today, it is not uncommon for each employee of a company or organization to have their own workstation for performing daily tasks such as word processing, creating spreadsheets, browsing the World Wide Web (WWW) and sending electronic mail via the Internet. Companies and organizations must employ local computer networks to link these individual workstation for electronic mail communications, Internet access, and sharing data and resources (e.g., peripherals). These networks, for a medium to large size company or organization, can easily contain over hundreds (if not thousands) of workstations.[0005]Consequently, there has been a dramatic (exponential) increase in the number of computers ...

AI Technical Summary

Benefits of technology

[0012]The present invention is a system and method for network address translation as an external service in the access server of a service provider. The system is a novel service provider access server which performs network address translation (NAT) or network address port translation (NAPT) for local office networks (i.e., stub networks). This allows NAT and NAPT functionally and associated hardware to be removed from stub network routers thereby significantly reducing the cost of such routers. The method involves receiving a datagram from the Internet whose destination is a globally unique Internet Protocol (IP) address, mapping the globally unique IP address to a locally significant IP address and routing the datagram to a stub router located within a stub network. The method further includes receiving a second datagram from the stub router whose source is a locally significant IP address, mapping the locally significant IP address to a globally unique IP address, and the routing the second datagram to the Internet.

Problems solved by technology

The necessity of including NAT features in the stub routers 106 purchased by individual corporations and organization adds to these routers' cost.

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