Dynamic RED Thresholding for Shared Buffer Switches
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Solution Overview
Problem
Conventional network switches with fixed RED parameters often mark packets too early, leading to unnecessary congestion marking in non-congested switches, and are not color-aware, resulting in inefficient data packet management.
Innovation Solution
Implementing a dynamic threshold technique with variable RED parameters, including minimum and maximum thresholds, to adjust the probability of packet discard based on available free space, and using weighted RED to differentiate between packet colors, ensuring equitable buffer sharing and timely congestion notification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If fixed RED parameters are used in conventional network switches, then the implementation is simple, but packets are marked too early causing unnecessary congestion marking in non-congested switches
Solution Approach 1:
The patent applies dynamics by transitioning from fixed RED parameters to dynamic parameters that adapt based on switch congestion state. The minimum threshold (min_th) and maximum threshold (max_th) are no longer static values but are adjusted according to the actual buffer occupancy and congestion conditions, allowing the system to respond flexibly to changing network states and avoid premature packet marking.
Solution Approach 2:
The patent implements parameter changes by modifying the RED threshold parameters (min_th and max_th) based on the switch's congestion state. When the switch is congested, different threshold values are applied compared to when it is not congested. This dynamic parameter adjustment ensures that packet marking occurs at appropriate congestion levels rather than prematurely, improving the accuracy of congestion notification.
2Ease of operation
If conventional RED marking approaches are used, then the implementation is straightforward, but the system is not color-aware resulting in inefficient data packet management
Solution Approach 1:
The patent applies local quality by differentiating packet handling based on packet color (classification). Instead of treating all packets uniformly, the system applies different RED parameters (min_th and max_th) to different packet colors. This allows high-priority packets to be handled differently from low-priority packets, improving overall data packet management efficiency while maintaining implementation feasibility through structured differentiation.
Solution Approach 2:
The patent implements universality by creating a color-aware RED mechanism that can handle multiple packet classifications simultaneously. The same RED framework is extended to work with different packet colors, allowing the system to provide differentiated service to various traffic types while using a unified congestion management approach. This multi-functional capability improves productivity without requiring completely separate systems for each packet type.
3Ease of operation
If static thresholds are used for packet marking, then the system is easy to implement, but buffer usage is not optimized and congestion notification is not timely
Solution Approach 1:
The patent applies dynamics by making the RED thresholds (min_th and max_th) dynamic rather than static. The thresholds are adjusted based on the switch's buffer occupancy and congestion state, allowing the system to optimize buffer usage in real-time. When the switch is congested, the thresholds are set to trigger marking at appropriate levels, providing timely congestion notification while maximizing buffer utilization.
Solution Approach 2:
The patent implements feedback by using the switch's congestion state and buffer occupancy information to adjust the RED parameters. The system continuously monitors buffer usage and feeds this information back to the RED mechanism, which then adjusts its marking behavior accordingly. This closed-loop feedback ensures that buffer usage is optimized and congestion is notified at the right time, improving productivity while maintaining ease of implementation through automated adjustment.
Data Source
AI summary
Embodiments of the present invention include systems and methods for adjusting RED configuration according to the available buffer space for a queue in a switch. In one or more embodiments, a method comprises the steps of: initializing minimum and maximum thresholds of RED associated with a queue; determining an available free space for the queue, wherein a data packet for the queue is discarded by a dynamic thresholding when a length of the queue reaches the available free space; determining an allowable free space (AFS) for the queue that is a multiplication of the available free space to an allowance factor (AF); and, when the length of the queue reaches the AFS, calculating a ratio of the minimum threshold to the maximum threshold and updating the maximum threshold to the AFS and updating the minimum threshold to a multiplication of the ratio to the AFS.