PFC Frame Congestion Control With Dynamic Rate Adjustment

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Solution Overview

Problem

Existing PFC (Priority-based Flow Control) mechanisms in network communication cause unreasonable pause times, leading to packet loss and failure in handling urgent data with time limits, and disrupt mechanisms requiring the PFC function to be turned off, such as TSN (Telecommunication Supporting Network).

Innovation Solution

A PFC frame-based congestion control method that enhances standard PFC frames by allowing temporary stop and deceleration of data transmission, using a reserved higher byte in the priority_enable_vector field to enable deceleration functions and redefine the time field, enabling flexible congestion control through PFC frames.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PFC completely stops data transmission of the corresponding priority to control congestion, then congestion is controlled, but packet loss occurs and unreasonable pause time is caused

Engineering Contradiction:

Improvecongestion control effectivenessVSAvoidpacket loss

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent transforms the static PFC pause mechanism into a dynamic rate control mechanism. Instead of completely stopping transmission with fixed pause times, the system dynamically adjusts the transmission rate of congested priority queues based on real-time congestion conditions, allowing continuous but regulated data flow that prevents packet loss while maintaining congestion control effectiveness

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the control parameter from binary pause/resume states to continuous rate adjustment parameters. By modifying transmission rate parameters rather than using fixed pause durations, the system can precisely control congestion while avoiding the packet loss associated with unreasonable pause times

Inventive Principle:

Principle #35Parameter changes

2Reliability

If PFC is used for congestion control, then congestion is managed, but mechanisms depending on urgent data with time limits fail

Engineering Contradiction:

Improvecongestion managementVSAvoidtime limit for urgent data

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies different rate control strategies to different priority queues based on their specific requirements. Urgent data queues with time limits receive higher rate priorities and shorter pause durations, while non-urgent queues receive stricter control. This localized differentiation ensures time-sensitive mechanisms function correctly while maintaining overall congestion management

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system dynamically adjusts rate control parameters for different priority levels based on congestion severity and data urgency. Time-critical traffic receives adaptive rate adjustments that preserve its time limits, while general traffic receives standard rate control, allowing the system to manage congestion without failing time-dependent mechanisms

Inventive Principle:

Principle #15Dynamics

3Reliability

If PFC function is activated for congestion control, then congestion is controlled, but preemption function fails

Engineering Contradiction:

Improvecongestion controlVSAvoidpreemption function

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments the flow control function into separate rate control modules for different priority queues. This segmentation allows the preemption function to operate independently on high-priority traffic while rate control manages overall congestion, enabling both functions to coexist without interference by dividing their operational domains

Inventive Principle:

Principle #1Segmentation

4Ease of manufacture

If standard PFC frames are used, then implementation is simple, but flexible congestion control is limited

Engineering Contradiction:

Improveimplementation simplicityVSAvoidflexible congestion control

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent enhances standard PFC frames by adding rate control parameters to existing frame structures, making them multi-functional. The extended frames can perform both traditional pause/resume operations and new rate control functions, providing flexible congestion control while maintaining compatibility with existing PFC infrastructure and avoiding complete system redesign

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP3905615B1PFC frame-based congestion control method and apparatus, system and storage medium

Publication Date: 2025.08.27 ZTE CORP

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AI summary

Disclosed by the present invention are a PFC frame-based congestion control method, comprising the following steps: when a physical link or a logical link is congested, a receiving terminal of a communication system acquiring the priority corresponding to a congested queue; on the basis of the congested queue, the receiving terminal determining deceleration parameters and/or a pause time corresponding to the priority; on the basis of the deceleration parameters, the pause time and the priority, the receiving terminal generating PFC frame-based control data; the receiving terminal transmitting a congestion control instruction comprising the control data to a transmission terminal of the communication system such that the transmitting terminal determines, on the basis of the control data, the transmission speed of data flow having the described priority. Further disclosed by the present invention are an apparatus, a system and a storage medium.