UE Identifier Retrieval Across NAT Through Network Function Mediation
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Solution Overview
Problem
In existing networks, User Equipment (UE) identifiers behind Network Address Translation (NAT) are not unique, preventing the Application Function (AF) from obtaining the required UE ID, which hinders appropriate actions for abnormal events due to the lack of UE private IP address information.
Innovation Solution
A method and system that enables a first function to trigger a first terminal to transmit a request message to a second function, allowing the second function to obtain and transmit the UE ID, supporting NAT address translation with minimal changes to the core network.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If NAT address translation is deployed behind UPF to share public IP addresses among multiple UEs, then IP address resource efficiency is improved, but UE identifier uniqueness is lost preventing AF from obtaining required UE ID
Solution Approach 1:
The patent introduces an intermediary mechanism (NEF or UPF) that mediates between the NAT-translated public IP addresses and the AF. This intermediary maintains the mapping relationship between public IP addresses and UE private IP addresses, and can retrieve/expose the original UE ID to the AF through standardized interfaces, thus preserving UE identifier uniqueness while maintaining NAT address translation efficiency
Solution Approach 2:
The patent adds another dimension to the address translation system by introducing a mapping layer that connects public IP addresses (NAT layer) with UE private IP addresses (original layer). This dimensional mapping allows the system to work with public IPs for resource efficiency while maintaining access to unique UE identifiers through the mapping relationship
2Reliability
If AF uses common UE addressing information (public IP and port) to detect abnormal events, then network security monitoring is improved, but the ability to request appropriate actions for specific UEs is lost
Solution Approach 1:
The patent implements a feedback mechanism where the AF can detect abnormal events using public IP addresses, then through the intermediary (NEF/UPF), obtain the corresponding UE private IP address and UE ID, and finally request appropriate corrective actions from the core network. This closed-loop feedback enables both detection and remediation capabilities
3Ease of manufacture
If UE IDs behind NAT are not unique, then NAT address translation functionality is maintained, but core network UE ID release capability cannot be fully utilized
Solution Approach 1:
The patent applies preliminary action by pre-establishing the mapping relationship between public IP addresses and UE identifiers in the intermediary (NEF or UPF) before the AF needs to access UE ID information. This allows the system to maintain NAT functionality while having UE ID retrieval capability ready when needed
Data Source
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AI summary
The present application discloses an information acquisition method. The method comprises: a first function triggers a first terminal to send a first request message to a second function, wherein the first request message is used for acquiring a first identifier of the first terminal; the first terminal sends the first request message to the second function; the second function receives the first request message sent by the first terminal; the second function obtains the first identifier on the basis of the first request message and a service of the second function; the second function sends the first identifier to the first terminal or the first function; and the first terminal or the first function receives the first identifier sent by the second function. The present application also discloses a first function, a second function, a third function, a first terminal, and a computer readable storage medium.