AS Migration NAT Continuity Without IP Stack Changes

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing communication technologies fail to maintain service continuity during application server (AS) migration without requiring modifications to the IP protocol stack, which limits standardization and widespread deployment.

Innovation Solution

Implementing Network Address Translation (NAT) parameters to reallocate and translate network addresses using a target User Plane Function (UPF)/Packet Switched Function (PSA), ensuring that data packets undergo double NAT translation to maintain the same source and destination addresses before and after AS migration, without modifying the kernel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the AS is migrated to a target AS with modified IP protocol stack context, then communication continuity is maintained, but the solution requires kernel modification capability which is not standardized and cannot be widely deployed

Engineering Contradiction:
Improvecommunication continuityVSAvoidstandardization and deployability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces a middlebox as an intermediary component deployed between the UE and the AS. This middlebox performs address translation and packet forwarding, enabling AS migration without requiring modifications to the AS kernel or IP protocol stack. The middlebox acts as a mediator that maintains communication continuity by translating addresses and forwarding packets appropriately during migration transitions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the communication function by separating the address translation and packet forwarding capabilities from the AS itself and placing them in a dedicated middlebox component. This segmentation allows the AS to be migrated independently without requiring kernel modifications, while the middlebox handles the complexity of address translation and maintains communication continuity.

Inventive Principle:
Principle #1Segmentation

2Reliability

If double NAT translation is performed by target UPF/PSA and target AS, then source and destination addresses remain unchanged ensuring communication continuity, but device complexity increases

Engineering Contradiction:
Improvecommunication continuityVSAvoidNAT translation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple NAT translation operations into a coordinated double NAT process. The first NAT translation is performed by the target UPF/PSA, and the second NAT translation is performed by the target AS through the middlebox. By merging these translations and coordinating them properly, the system maintains original source and destination addresses while enabling AS migration, distributing the complexity across multiple components rather than concentrating it in one device.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4247024B1Method for implementing communication continuity and related device
Publication Date: 2026.03.04 TENCENT TECHNOLOGY (SHENZHEN) CO LTD
  • EP4247024B1 patent drawingFigure 1~2
  • EP4247024B1 patent drawingFigure 3
  • EP4247024B1 patent drawingFigure 4

AI summary

Provided in the embodiments of the present disclosure are a method for implementing communication continuity and a related device. The method is applied to an AF corresponding to a LTE, and the LTE establishes a connection with a source AS by using allocated UE source network address information. The method comprises: determining to transfer from a source AS to a target AS; transmitting a first NAT parameter to an SMF, so that the SMF determines a target UPF/PSA, wherein the target UPF/PSA is used for reallocating LTE target network address information to a LTE, generating a second NAT parameter according to the first NAT parameter, UE source network address information and the LTE target network address information, returning the second NAT parameter to the SMF, and performing NAT on a received data packet according to the second NAT parameter; acquiring the second NAT parameter from the SMF; and configuring a third NAT parameter for the target AS according to the second NAT parameter, and transferring from the source AS to the target AS, so that the target AS performs NAT on the data packet according to the third NAT parameter.