Router Queue Management via Adaptive Packet Dropping

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Solution Overview

Problem

Current network elements, such as routers, face challenges in managing queue lengths and packet delays, particularly with bursty traffic, leading to high round-trip delays and synchronization issues, which negatively impact application performance and user experience.

Innovation Solution

Classifying data items into subsets based on their source and destination indications, determining performance characteristics using time measures like round-trip time (RTT), and forwarding data items according to these characteristics to prioritize and manage network traffic effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If tail-drop discipline is used to manage queue fullness, then queue management is simple, but round-trip delays become very high and bursty traffic is penalized

Engineering Contradiction:
Improvequeue management complexityVSAvoidround-trip delay
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by proactively dropping packets before the queue becomes full, rather than waiting until it is full and then dropping packets (tail-drop). This early intervention prevents long delays from accumulating in the queue while maintaining simple queue management logic at the router.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamics by making the packet dropping behavior adaptive based on queue conditions and traffic characteristics. The system dynamically adjusts which packets to drop and when, rather than using a static tail-drop approach, thereby reducing delays while maintaining manageable complexity.

Inventive Principle:
Principle #15Dynamics

2Loss of time

If AQM techniques are used to selectively drop packets before queue is full, then round-trip delays are reduced and congestion is signaled earlier, but device complexity increases

Engineering Contradiction:
Improveround-trip delayVSAvoidqueue management complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the packet dropping decision into distinct components: identifying candidate packets for dropping, evaluating their impact, and selectively dropping them. This structured approach reduces the complexity burden of AQM by organizing the decision-making process into manageable segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements feedback mechanisms where the system monitors queue conditions and traffic patterns, then adjusts packet dropping decisions accordingly. This feedback loop enables the system to maintain low delays while managing complexity through adaptive behavior based on observed network conditions.

Inventive Principle:
Principle #23Feedback

3Speed

If traffic prioritisation is used to route higher priority traffic first, then bandwidth and latency are improved for important traffic, but device complexity increases due to classification requirements

Engineering Contradiction:
Improvepacket forwarding speedVSAvoidtraffic classification complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent applies local quality by implementing prioritization selectively for specific traffic types or conditions rather than universally. This allows the system to improve speed for important traffic while avoiding the complexity of classifying all traffic, by applying different handling rules to different local contexts.

Inventive Principle:
Principle #3Local quality

4Quantity of substance

If buffers are made larger to handle bursty traffic, then queue capacity increases, but cost increases and round-trip delays increase when queues are full

Engineering Contradiction:
Improvequeue capacityVSAvoidround-trip delay
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The patent applies preliminary action by proactively managing queue contents before they become full, using selective packet dropping to prevent queue overflow. This allows the system to maintain smaller buffers while avoiding the high delays that occur when large buffers fill up, by intervening early to keep queue lengths manageable.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS10523571B2Processing data items in a communications network
Publication Date: 2019.12.31 BRITISH TELECOM PLC
  • US10523571B2 patent drawing
  • US10523571B2 patent drawing
  • US10523571B2 patent drawing

AI summary

Methods and apparatus are disclosed for processing data items received at a network element in a communications network. In particular, methods and apparatus are disclosed for processing data items such as packets received at a network element such as a router or other such packet-forwarding network element (20) from a source (1, 1′) and which are intended to be forwarded towards an intended receiver (2, 2′) in a communications network such as a network operating according to the Internet Protocol.