Video Conferencing Test Suite

Our video conferencing test suite measures roundtrip latency and packet loss to the most popular online video conferencing services. Many different protocols and communications are used during video conferencing. Our measurements focus on traffic to the video and audio relay servers, as problems on this link directly manifest as connectivity and quality issues to end users.

Supported Video Conferencing Services

The supported video conferencing services are:

• Google Meet

• GoToMeeting

• Microsoft Teams

• Skype (consumer)

• Cisco Webex

• Zoom

Video Conferencing Test Methodology

A different approach is required for each different video conferencing provider. All measurements are carried out using UDP packets, either to the STUN (Simple Traversal of User Datagram Protocol (UDP) Through Network Address Translators (NATs)) services offered by the providers, or over a proprietary protocol (most notably in the case of Zoom).

Some providers make use of anycast addresses for connecting the user to the nearest video conferencing service, while others use unicast and handle load balancing and failover separately.

For services that use an IP prefix range of addresses, the test is probing over the range using ICMP. In the order of lowest round-trip-times (RTTs), it selects the first server that responds to STUN probing and then performs measurements.

We have catalogued the list of hostnames and addresses used by each provider and have tested from Europe, North America, South America, the Middle East, Oceania, and Asia to ensure representatives.

In some cases, there is a difference between licensed and unlicensed video conferencing clients. This is captured by the test as well, for example in Oceania, where only licensed versions of some services give access to local datacenters.

The video conferencing test fully supports IPv4 and IPv6. It may optionally be run with DNS resolution performed via DNS-over-HTTPS or DNS-over-TLS, instead of using the default system resolver.

Video Conferencing Test Metrics

For each video conferencing service and endpoint, we measure:

• Average round trip latency for 10 UDP packets (by default).

• Minimum, maximum, median, and standard deviations for the latency measurements.

• The number of packets sent and received.

• The IP address of the endpoint.

Video Conferencing Test Example

In 2020, we investigated video conferencing performance in the UK. Most of the services had latency between 20 ms and 30 ms. The one exception was Zoom, which saw average latencies of around 135 ms. This is because Zoom were relaying all audio/video traffic via their servers in the US, regardless of the country the user was located in.

Showing latency to the six different video conferencing services measured, split by hour of day.

Video Conferencing Test Configuration Options

Configure your video conferencing test suite via the following tabs and fields.

Basic Settings

The basic settings tab contains only the settings detailed within Configuring Common Test Settings.

• The Target setting is not configurable as each test execution automatically measures all supported video conferencing targets.

• Interval defaults to every 8 hours.

Advanced Settings

Network

• DSCP: Defaults to “Best Effort (DSCP 0) - Default”. Choose also from:

  • AF 11 (DSCP 10)

  • AF 12 (DSCP 12)

  • AF 13 (DSCP 14)

  • AF 21 (DSCP 18)

  • AF 22 (DSCP 20)

  • AF 23 (DSCP 22)

  • AF 31 (DSCP 26)

  • AF 32 (DSCP 28)

  • AF 33 (DSCP 30)

  • AF 41 (DSCP 34)

  • AF 42 (DSCP 36)

  • AF 43 (DSCP 38)

  • CS 1 (DSCP 8)

  • CS 2 (DSCP 16)

  • CS 3 (DSCP 24)

  • CS 4 (DSCP 32)

  • CS 5 (DSCP 40)

  • CS 6 (DSCP 48)

  • CS 7 (DSCP 56)

  • EF (DSCP 46)

  • Voice Admit (DSCP 44)

DNS Resolver

• Override system default DNS: Manually sets the DNS server queried for the target domain. Otherwise, system default runs Do53 over UDP. Defaults to disabled.

  • If enabled, a dropdown appears where you can select a server address type and enter a server address. The dropdown defaults to “DNS server address”. If you choose this option, you must input a specified Do53 server for name resolution (UDP with TCP fallback). Choose also from:

    • DNS-over-HTTPS resolver URL: Uses a custom DoH server for name resolution: fully qualified resolver URL must begin with “https://” and end with “/dns-query”.

    • DNS-over-TLS resolver IP: Uses a custom DoT server for name resolution: input a resolver IP address.

Agent Testing Thresholds

• Cross-traffic, downlink/dplink: Defaults to 25,000 bytes per second down/up.

• CPU usage: Defaults to 30%. Range is from 1-100%.