The QualityGuard Congestion Response System

A Sandvine Technology Showcase

Network congestion is defined as the situation in which an increase in data transmissions results in a proportionately smaller (or even a reduction in) throughput. In other words, when a network is congested, the more data one tries to send, the less data is actually successfully sent.

There are many factors that must be considered and understood to critically evaluate congestion management systems, as the accuracy of detection mechanisms varies widely and many factors determine how effective the management policies themselves are in alleviating the congestion. Only by linking an accurate trigger with a precise management policy can CSPs achieve their congestion management goals.

QualityGuard is a closed-loop dynamic control system for network congestion management that automatically measures access resource latency in real-time and continuously works to provide the optimum output to provide good QoE to the vast majority of attached subscribers. QualityGuard performs the following two main functions:

  1. Automatically detects congestion by measuring real-time subscriber QoE via aRTT latency
  2. Automatically removes or prevents congestion by shaping traffic until achieving a maximum throughput rate just short of the point where the access resource would slide into congestive collapse, which can be thought of as the “target goodput ”

QualityGuard is the most effective means of achieving a perfect balance between cost-savings through the extension of access resource lifetime and the preservation of good QoE for the vast majority of subscribers during times of congestion.

UPDATED : 2017-04-17 09:51:43