Packet Relay Device Congestion Control via Multi-Stage Queue Thresholds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing congestion control technologies in packet relay devices often lead to a sudden decrease in network throughput due to uniform reduction of threshold values across all connections, causing unnecessary restrictions in data communication.
Innovation Solution
A packet relay device with a multi-stage queue structure and separate queue length measurements for each queue and the total queue length, allowing for individualized congestion control by determining congestion notifications based on specific arithmetic expressions and threshold values, thereby optimizing network throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If uniform threshold value reduction is applied to all connections for congestion control, then congestion suppression is achieved, but overall network throughput decreases suddenly
Solution Approach 1:
The patent divides the single uniform threshold value into multiple connection-specific threshold values (first threshold value for each connection). This segmentation allows different connections to have different threshold levels based on their individual queue lengths, enabling selective congestion notification only to connections that actually need it, thereby maintaining throughput for non-congested connections while still suppressing congestion where it occurs.
Solution Approach 2:
The patent applies local quality by making threshold values connection-specific rather than uniform across all connections. Each connection receives a tailored threshold value based on its own queue length characteristics, allowing congestion control to be applied locally only where necessary. This ensures that connections with short queues are not unnecessarily restricted, preserving overall network throughput while maintaining reliability for congested connections.
2Reliability
If threshold values are reduced to suppress congestion, then packet buffering is improved, but packet loss increases
Solution Approach 1:
The patent implements dynamic threshold values that adjust based on current queue length conditions. When queue length exceeds a reference value, the threshold is reduced to trigger congestion notification; when queue length is below the reference value, the threshold is increased or reset. This dynamic adjustment allows the system to respond adaptively to changing traffic conditions, improving packet buffering during congestion while avoiding unnecessary packet loss during normal operation.
Solution Approach 2:
The patent employs feedback mechanisms where the congestion notification determination unit continuously monitors queue length and compares it against dynamically adjusted threshold values. When the queue length exceeds the threshold, a congestion notification is sent back to the transmitting device, which then reduces its transmission rate. This feedback loop allows the system to maintain reliable packet buffering by triggering control actions only when actually needed, rather than using static reduced thresholds that would cause unnecessary packet loss.
Data Source
AI summary
A packet relay device is equipped with a buffer memory including a plurality of queues for temporarily storing packets, and a storage unit for storing the first queue lengths indicating the respective queue length of each of the queues and a second queue length indicating a value according to a total of the plurality of first queue lengths. When the packet relay device receives packets, it discerns the queue to which the received packet belongs from among the plurality of queues, and temporarily stores the packet in relation to the discerned queue within the buffer memory. Then, the first queue length and the second queue length are updated, and a determination is made of whether or not to send a congestion notification to the packet sending source according to the first queue length corresponding to the discerned queue, and to the second queue length.