Proxy Server Remote Access for NAT-Shielded Devices
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Solution Overview
Problem
Service providers face challenges in remotely troubleshooting network devices with private IP addresses, as these devices are shielded from remote access due to the home gateway functioning as a firewall and NAT router, lacking a standard mechanism for initiating a remote HTTP connection.
Innovation Solution
A system and method that establish communication between a client device with a private address and a proxy server, enabling relay communications from an administrator device through the proxy server, allowing remote administration and troubleshooting despite the presence of intermediate NATs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a home gateway functions as a firewall and NAT router to shield devices, then device security and privacy are improved, but remote access capability deteriorates
Solution Approach 1:
The client device initiates an outbound connection to the proxy server before remote access is needed. This preliminary action creates a pre-established communication channel through the NAT router, allowing future inbound connections from administrators to be relayed through this existing path without requiring the NAT router to be reconfigured or the firewall rules to be changed.
Solution Approach 2:
A proxy server is introduced as an intermediary component between the administrator's device and the client device behind the NAT router. The proxy server receives HTTP requests from administrators, relays them through the pre-established connection to the client device, and forwards responses back. This intermediary enables remote access while maintaining the NAT router's security function of blocking direct inbound connections.
2Object-affected harmful factors
If NAT address translation is used to hide private IP addresses, then network security is improved, but standard remote HTTP connection mechanisms fail
Solution Approach 1:
The proxy server acts as a mediator that translates and relays HTTP requests between the external administrator and the internal client device. It receives standard HTTP requests from administrators using common web browsers, and forwards them through the NAT-protected network to the target device, making the system compatible with standard remote HTTP connection mechanisms while preserving NAT security.
Solution Approach 2:
The system performs preliminary actions by establishing an outbound connection from the client device to the proxy server during device initialization or before remote access is required. This pre-established connection bypasses the need for inbound port forwarding or NAT configuration changes, enabling standard HTTP connection mechanisms to work through the NAT router without compromising security.
3Reliability
If devices behind gateway are shielded from remote connections, then firewall effectiveness is improved, but troubleshooting capability deteriorates
Solution Approach 1:
The proxy server serves as a troubleshooting intermediary that enables support personnel to remotely access and diagnose issues on client devices without disabling or bypassing the firewall. All troubleshooting traffic flows through the proxy server, which maintains the firewall's blocking of direct inbound connections while providing authorized remote access for diagnostic and repair activities.
Solution Approach 2:
The client device performs preliminary action by initiating and maintaining an outbound connection to the proxy server. This pre-established connection path allows troubleshooting traffic to flow through the firewall in the permitted outbound direction, enabling remote diagnostic capabilities while preserving the firewall's effectiveness at blocking unsolicited inbound connections.
Data Source
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AI summary
According to one or more embodiments of the present invention, a proxy server includes a memory and a communication unit. The memory is configured to store and retrieve a client device identifier and an associated client device transport address, while the communication unit is configured to send and receive messages. The communication unit is configured to receive an identification message according to a first protocol from a client device through at least one intermediate network address translator (NAT). The identification message includes the client device identifier and conveys the client device transport address. The communication unit is configured to receive a request message from an admin device including the client device identifier. The proxy server is configured to retrieve the associated client device transport address and instruct the client device to open a connection with the proxy server according to a second protocol that is different from the first protocol.