Citrix SD-WAN

Application QoE

Application QoE is a measure of Quality of Experience of applications in the SD-WAN network. It measures the quality of applications that flow through the virtual paths between two SD-WAN appliances. The Application QoE score is a value between 0 and 10. The score range that it falls in determines the quality of an application.

Quality Range
Good 8–10
Fair 4–8
Poor 0–4

Application QoE score can be used to measure quality of applications and identify problematic trends.

You can define the quality thresholds for real-time and interactive appliances using QoE profiles, and map these profiles to applications or applications objects.

Note:

To monitor Application QoE, it is essential to enable Deep Packet Inspection. For more information, see Application classification

Real-time application QoE

The Application QoE calculation for real-time applications uses a Citrix innovative technique, which is derived from MOS score.

The default threshold values are:

  • Latency threshold: 160 ms
  • Jitter Threshold: 30 ms
  • Packet loss threshold: 2%

A flow of a real-time application that meets the thresholds for latency, loss, and jitter is considered to be of good quality.

QoE for Real-time applications is determined from the percentage of flows that meet the threshold divided by the total number of flow samples.

QoE for Real-time = (No of flow samples that meet the threshold / Total no of flow samples) * 100

It is represented as QoE score ranging from 0 to 10.

You can create QoE profiles with custom threshold values and apply to applications or application objects.

Note:

The QoE value can be zero if the network conditions are outside of the configured thresholds for real-time traffic.

Interactive application QoE

The Application QoE for interactive applications uses a Citrix innovative technique based on packet loss and burst rate thresholds.

Interactive applications are sensitive to packet loss and throughput. Therefore, we measure the packet loss percentage, and the burst rate of ingress and egress traffic in a flow.

The configurable thresholds are:

  • Packet loss percentage.
  • Percentage of expected egress burst rate in comparison to the ingress burst rate.

The default threshold values are:

  • Packet loss threshold: 1%
  • Burst rate: 60%

A flow is of good quality if the following conditions are met:

  • The percentage loss for a flow is less that the configured threshold.

  • The egress burst rate is at least the configured percentage of ingress burst rate.

Configuring application QoE

Map application or application objects to default or custom QoE profiles. You can create custom QoE profiles for real-time and interactive traffic.

To create custom QoE profiles:

  1. In the Configuration Editor, navigate to Global > Application QoE > QoE Profiles and click +.

  2. Enter value for the following parameters:

    • Profile Name: A name to identify the profile that sets thresholds for real-time and interactive traffic.
    • Real-time: Configure thresholds for traffic flows that hit the real-time QoS policy. A flow of a real-time application that meets that below thresholds for latency, loss, and jitter is considered to be of good quality.

      • One Way latency: The latency threshold in milliseconds. The default QoE profile value is 160 ms.
      • Jitter: The jitter threshold in milliseconds. The default QoE profile value is 30 ms.
      • Packet Loss: The percentage of packet loss. The default QoE profile value is 2%.
    • Interactive: Configure thresholds for traffic flows that hit the interactive QoS policy. A flow of an interactive application that meets that below threshold for burst ratio and packet loss is considered to be of good quality.
      • Expected Burst Rate: The percentage of expected burst rate. The egress burst rate should be at least the configured percentage of ingress burst rate. The default QoE profile value is 60%.
      • Packet loss per flow: The percentage of packet loss. The default QoE profile value is 1%.

        localized image

  3. Click Apply.

To map applications or application objects with QoE profiles:

  1. In the Configuration Editor, navigate to Global > Application QoE > QoE Configuration and click +.
  2. Select values for the following parameters:

    • Type: A DPI application or an application object.
    • Application: Search and select an application or application object based on the selected Type.
    • QoE Profile: Select a QoE profile to map to the application or application object.

      localized image

  3. Click Apply.

You can map up to 10 applications or application objects with QoE profiles. You can view the Application QoE reports on SD-WAN Center. For more information see, the Application QOE report report.

Application QoE