PFCP Interface Reporting Between UP and CP Devices for BNG Subscriber Control

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Solution Overview

Problem

In a broadband network gateway (BNG) with control plane and user plane separation (CU separation), the control plane (CP) device lacks information about the user plane (UP) device's interfaces, limiting its functionality, such as controlling access subscribers.

Innovation Solution

The UP device generates a first packet forwarding control protocol (PFCP) message containing interface information, including an index, type, bandwidth, and other details, and sends it to the CP device, enabling the CP to manage terminals effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the BNG adopts a CU separation architecture to improve network flexibility and functionality, then the control plane and forwarding plane are separated, but the CP device cannot obtain interface information of the UP device, leading to functional limitations

Engineering Contradiction:

Improvenetwork flexibilityVSAvoidinterface information

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The UP device actively reports interface information to the CP device through PFCP messages, establishing a feedback mechanism that ensures the CP device receives necessary interface data without requiring direct querying or manual configuration

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The PFCP message serves as an intermediary carrier that transfers interface information from the UP device to the CP device, enabling communication between the two separated plane devices through a standardized protocol interface

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the CP device lacks interface information to maintain architectural separation, then the CU separation is achieved, but the CP device cannot control access subscribers or perform authentication functions

Engineering Contradiction:

Improvearchitectural separationVSAvoidsubscriber control capability

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The UP device provides feedback to the CP device by reporting interface information including interface indices and characteristics, enabling the CP device to make informed decisions for subscriber control and authentication without compromising architectural separation

Inventive Principle:

Principle #23Feedback

Data Source

PatentEP4135401B1Communication method, up device and CP device

Publication Date: 2025.09.03 HUAWEI TECH CO LTD

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AI summary

This application provides a communication method, a UP device, and a CP device, and pertains to the field of communications technologies. In the method, the UP device reports interface information to the CP device by using PFCP. Specifically, the UP device carries the interface information in a PFCP message, and transmits the PFCP message to the CP device. The CP device can obtain the interface information of the UP device from the PFCP message, which ensures that the CP device can sense the interface information of the UP device. Therefore, limitation on functions caused by insufficiency of interface information obtained by the CP device is resolved to some extent, helping the CP device implement various functions by using the interface information of the UP device.