Modular NAT Function in 5G Core via Service-Based Interface
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Solution Overview
Problem
Current 5G systems lack a modular and service-based architecture for integrating Network Address Translation (NAT) functionality, which is essential for managing IP address translation between IPv4 and IPv6 domains, and this integration should not disrupt the existing vendor ecosystem or significantly impact existing systems.
Innovation Solution
Implementing a modular, service-based architecture for the User Plane Function (UPF) in 5G systems that utilizes the Service-Based Interface (SBI) for NAT Network Function Service (NFS) communication, allowing the Session Management Function (SMF) to discover and control NAT functionality on a per-DNN, per-slice, per-PDU session, per-subscriber, or per-IP basis, while maintaining backwards compatibility with the Packet Forwarding Control Protocol (PFCP) in the N4 interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If NAT functionality is integrated into the 5G Core Network, then IP address management capability is improved, but system complexity increases
Solution Approach 1:
The patent segments NAT functionality into a separate, independent Network Function (NAT NF) that can be deployed as a standalone service or integrated into the UPF. This segmentation allows the NAT function to be added to the 5G Core Network without fundamentally redesigning existing components, thereby improving IP address management capability while controlling system complexity through modular architecture.
Solution Approach 2:
The NAT Network Function is designed with multi-functionality to support various NAT types (NAT44, NAT46, NAT64) and can serve multiple purposes including IPv6-IPv4 translation, carrier-grade NAT, and IP address conservation. This universal design enables a single NF to handle diverse IP address management requirements without proportionally increasing system complexity.
2Ease of manufacture
If modular service-based architecture is implemented for NAT, then ease of integration is improved, but control mechanism complexity increases
Solution Approach 1:
The patent introduces a Service-Based Interface (SBI) as an intermediary layer between the NAT Network Function and other 5G Core Network functions (such as SMF). This SBI uses standardized HTTP/2 protocols with well-defined APIs, enabling easy integration of the NAT function while simplifying control mechanisms through a uniform interface that abstracts the underlying complexity of NAT operations.
Solution Approach 2:
The control mechanism leverages parameter changes in the SBI interface to dynamically configure NAT behavior. By modifying parameters such as NAT type, translation rules, and address pools through standardized API calls, the system achieves flexible control without complex control logic, thereby improving ease of integration while keeping control mechanism complexity manageable.
3Adaptability or versatility
If NAT functionality is added to existing 5G systems, then IP address translation capability is improved, but impact on existing systems increases
Solution Approach 1:
By segmenting NAT functionality into a separate Network Function that operates independently from existing 5G Core components, the patent ensures that adding IP address translation capability does not disrupt existing systems. The NAT NF can be deployed as a side-service or integrated into UPF without modifying core 5G protocols, thereby maintaining reliability while improving IP address translation capability.
Solution Approach 2:
The Service-Based Interface acts as an intermediary that isolates the NAT function from existing 5G Core Network functions. This interface layer ensures that the NAT capability can be added without forcing changes to existing systems, as other functions communicate with the NAT NF through standardized SBI protocols rather than requiring modifications to their internal architectures, thus minimizing impact on existing systems.
Data Source
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AI summary
A method for supporting Network Address Translation, NAT, functionality in a 5G Core Network, CN, the 5G CN comprising at least one User Plane Function, UPF, at least one Session Management Function, SMF, and at least one Network Repository Function, NRF, wherein the UPF comprises a UPF Network Function, NF, profile and the UPF NF profile contains at least one NAT NF Service, NAT NFS, instance description, the method comprising: registering, at the NRF, the UPF NF profile, wherein the NAT NFS instance description includes information regarding which NAT functionality it supports.