Application Quality of Experience (AppQoE) Overview

Application Quality of Experience (AppQoE) aims to improve the user experience at the application level by constantly monitoring the class-of -service parameters and SLA compliance of application traffic and ensuring that the application data is sent over the most SLA-compliant link available. AppQoE is supported on both hub-and-spoke and full mesh topologies when the SD-WAN mode is set to Real Time-Optimized. AppQoE is implemented as a book-ended solution, where both the ends have SRX series devices or vSRX instances that run the same version of Junos OS with the same configuration.

AppQoE is enabled only when the SD-WAN mode for the tenant is set to Real Time-Optimized. In the default mode, which is Bandwidth-Optimized, CSO uses RPM probes to monitor link-level traffic.

On SD-WANs in the real time-optimized mode, CSO monitors the application traffic for SLA compliance. The CPE device uses this data to move the application traffic from links that fail to meet the SLA requirements to links that meet SLA.

To monitor the SLA compliance of the link on which the application traffic is sent, CSO sends inline probes, called as passive probes, along with the application traffic. To identify the best available link for an application in case the active link fails to meet the SLA criteria, CSO constantly monitors and collects SLA compliance data for other available links. The probes that CSO sends over the other links to check the SLA compliance are called as active probes. The active probes are carried out based on the probe parameters that you configure.

Link switching is done at the application level by the CPE device. That is, only the traffic corresponding to the application that reported the SLA violation is moved to a link that meets the specified SLA. The remaining traffic remains on the same link until those applications report an SLA violation.

You can configure traffic type profiles to specify the class-of-service parameters and the probe parameters for each traffic type. When you create an application SLA profile, you can link that with a traffic type profile and specify the SLA parameters and SLA sampling criteria for the SLA profile.. The Application SLA profile is then linked to an SD-WAN policy intent, which can be deployed to implement AppQoE.

From the Application SLA Performance page, you can view the application-level SLA performance information and whether AppQoE is enabled. You can also view applications-level SLA performance details such as packet loss, RTT, jitter, and the number of probes.

The following sections describe the prerequisites, limitations, and workflow for configuring AppQoE.

Workflow

1. Service provider administrators review the default traffic type profiles, enable the required profiles, modify the default profiles, or create new profiles.

2. Add a tenant with the SD-WAN mode set to real time-optimized. For information about adding a tenant, see Adding a Single Tenant.

3. Service provide administrator or tenant administrator can create an application SLA profile and associate a traffic type profile with that. For more information about creating an application SLA profile, see Creating SLA Profiles.

4. Service provide administrator or tenant administrator can associate the SLA profile with an SD-WAN Policy and deploy the policy. For more information see Creating SD-WAN Policy Intents and Deploying Policies.

5. Service provider administrator or tenant administrator can view application-level SLA performance details from the Application SLA Performance page. For more information, see Monitoring Application-Level SLA Performance for real time-optimized SD-WAN.