Security Software
Various security and antivirus programs allow you to monitor network traffic. This involves checking the content and patterns of data traffic and influencing the data stream. This can negatively impact performance measurements. Some security programs completely block the cnlab UX test (speed test), while others use a local proxy to check the content. This can lead to very low or very high data rates. To ensure optimal measurements, either disable the security software for the duration of the test or configure an exception for the respective speed test program.

Virtual Private Network (VPN)
When a performance measurement is carried out with a VPN enabled, the performance of the VPN and VPN provider is almost exclusively checked rather than the performance of the internet connection. VPN connections are usually less powerful than the actual internet connection. This is partly due to the greater distance between the test client and the target server, capacity bottlenecks, and routing through different provider networks.

• Information on Using a VPN
  • When you use a VPN, you connect to one of the provider's endpoints and access the internet from there. These endpoints can be located in various places in Switzerland, the EU, or around the world. For example, let's consider a VPN endpoint in the Netherlands. With the VPN enabled, your data is sent from Switzerland to the Netherlands and then to the internet. For a performance test, the data is sent to the Netherlands and then back to Switzerland. The test data must pass through various provider networks. Each network involved impacts the measurement: the data rate is reduced and response times increase.
  • The VPN provider makes its infrastructure available to all users simultaneously and in parallel. This means they share the available bandwidth at the VPN endpoint. For example, if the VPN endpoint has a 10 Gbit/s network connection and supports 500 parallel sessions, each user has an average of only 20 Mbit/s. This reduces the measured data rate.
• Action Steps for Performance Measurement
  • Deactivate the VPN for the measurement.
• Detection in the CNLAB UX Test Apps
  • The detection of VPNs in the cnlab UX Test Apps is based on the local routing of test packets. The collected information is used to determine whether a VPN is being used. The cnlab UX Test Apps only detect the use of a VPN, not the type of VPN or VPN provider.
  • There are many different VPN providers, technologies, and settings. Therefore, the cnlab UX Test Apps may not detect all VPNs. VPNs that do not affect the test data are not displayed in the app.
  • VPNs used on routers in the network path cannot be detected by the cnlab UX Test Apps.