NAT Traversal via Non-IP Messaging Inversion

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Solution Overview

Problem

Existing IP communication systems face challenges in establishing connections between an originating node in a public network and a terminating node in a private network, particularly due to limitations in NAT traversal, where the terminating node lacks a static public identity and mobile networks often restrict IP traffic for security reasons, making it difficult for IP devices to initiate connections across mobile networks.

Innovation Solution

A system that enables an originating node in a public network to communicate with a terminating node in a private network by sending a non-IP-based message, allowing the terminating node to initiate IP-based communication, using a middleware layer to create virtual sockets and manage network connections without requiring special configurations or modifications to existing TCP/IP applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a NAT is used to translate private IP addresses to public IP addresses, then address conservation and privacy are improved, but the ability of IP devices to initiate connections to terminating nodes is worsened

Engineering Contradiction:

ImproveIP address conservationVSAvoidconnection initiation capability

Core Design Contradiction:

Quantity of substanceVSEase of operation

Solution Approach 1:

Instead of having the originating node initiate a connection to the terminating node behind NAT, the patent inverts the approach by having the terminating node initiate the connection back to the originating node. This is achieved by sending a non-IP-based message (like SMS or email) to the terminating node, which then establishes an IP connection to the originating node, thereby bypassing the NAT traversal problem while preserving address conservation

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces a non-IP-based communication channel (SMS, email, or other messaging systems) as an intermediary to facilitate the connection establishment. This intermediary channel allows the originating node to communicate connection requests to the terminating node without requiring direct IP connectivity, thus working around the NAT limitation

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If firewalls are configured to block incoming IP traffic for security reasons, then network security is improved, but the ability to establish incoming connections to private network nodes is worsened

Engineering Contradiction:

Improvenetwork securityVSAvoidincoming connection capability

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent circumvents firewall restrictions by inverting the connection direction. Instead of attempting to establish an incoming connection to the private network node (which is blocked by firewalls), the terminating node initiates an outgoing connection to the originating node, which is permitted by firewall security policies

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

A non-IP-based messaging intermediary is used to communicate connection requests through the firewall. Since firewalls typically allow outbound traffic and certain messaging protocols, this intermediary channel enables the originating node to relay connection information to the terminating node without being blocked

Inventive Principle:

Principle #24Intermediary (Mediator)

3Quantity of substance

If mobile networks use dynamic IP allocation and NAT, then IP address efficiency is improved, but the ability of IP devices to identify and connect to terminating nodes is worsened

Engineering Contradiction:

ImproveIP address efficiencyVSAvoidterminating node identification

Core Design Contradiction:

Quantity of substanceVSLoss of information

Solution Approach 1:

The patent uses non-IP-based messaging systems as an intermediary to transmit identifying information about the terminating node. Since these messaging systems are not subject to IP address translation or dynamic allocation issues, they provide a reliable channel for conveying node identification information from the originating node to the terminating node

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary actions by establishing the non-IP-based communication channel and exchanging identification information before attempting to establish the actual IP connection. This preliminary exchange of information through the more reliable messaging channel enables subsequent connection establishment despite dynamic IP allocation

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS8265069B2System, terminal, method, and computer program product for establishing a transport-level connection with a server located behind a network address translator and/or firewall

Publication Date: 2012.09.11 NOKIA TECHNOLOGIES OY

AI summary

A system, terminating node, method, and computer program product enable an originating node in a public network to communicate with a terminating node in a private network by sending a non-IP-based message from the originating node to the terminating node, thereby causing the terminating node to initiate IP-based communication with the originating node. Because a client behind a NAT and/or firewall in a private network will generally be able to connect and establish a TCP/IP session to a server in the public network, this improves the ability of the originating node to communicate with the terminating node whenever desired. Once the IP-based communication session is established, the two nodes can exchange data in both directions until the connection between them is closed by either node. As such, unmodified client and server TCP/IP applications are able to traverse a NAT/firewall, without the need for configuration of an intermediary node.