Packet Transport Traffic Management via WRED Queue Segmentation

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Solution Overview

Problem

In packet transport systems, operating multiple functions such as QoS, OAM, and protection simultaneously leads to a reduction in packet processing rate and an increase in error rate due to global synchronization between data and control packets, particularly when traffic exceeds link capacity.

Innovation Solution

The method involves calculating the average queue size based on link capacity and applying different allowable lengths and drop probabilities to packets using a weighted random early drop (WRED) algorithm, optimizing parameters to prevent global synchronization and manage traffic congestion by marking packets as green, yellow, or red, and applying specific WRED profiles to each queue level.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple functions (QoS, OAM, protection) are operated simultaneously in packet transport system, then network reliability and service protection are improved, but packet processing rate is reduced and error rate is increased

Engineering Contradiction:

Improvenetwork reliabilityVSAvoidpacket processing rate

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent segments traffic into different queues based on packet marking (green, yellow, red) and applies different WRED profiles to each queue. This segmentation allows OAM packets to be handled separately from data traffic, preventing global synchronization while maintaining network reliability functions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different WRED profiles with different parameters (allowable length, probability of disuse) to different queues based on their specific requirements. OAM packets in green queues receive more lenient treatment while data packets in yellow/red queues receive stricter control, optimizing both reliability and processing rate locally for each traffic type.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If traffic exceeds link capacity, then more functions can be supported, but global synchronization occurs causing packet loss and increased error rate

Engineering Contradiction:

Improvefunction support capabilityVSAvoidpacket loss rate

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies WRED (Weighted Random Early Drop) mechanism that proactively monitors queue sizes and begins dropping packets before queues become full. By calculating average queue size and comparing it against thresholds, the system preemptively prevents global synchronization between data and control packets, reducing packet loss when traffic exceeds link capacity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes WRED parameters (allowable length, probability of disuse) based on packet marking and queue level. Different queues have different WRED profiles that dynamically adjust dropping behavior, allowing the system to adapt to varying traffic conditions and prevent global synchronization while maintaining function support capability.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9215187B2Packet transport system and traffic management method thereof

Publication Date: 2015.12.15 ELECTRONICS & TELECOMM RES INST

AI summary

A method of managing traffic of packet transport system according to some embodiments of the inventive concept may include calculating an average queue size of input traffic with reference to a link capacity; and differently applying allowable length and probability of disuse with respect to the calculated average queue size according to marking information with respect to packets of the input traffic. The input traffic includes a CCM packet for OAM.