Teams call quality troubleshooting checklist

Rules out WiFi interference and packet loss in one step. Plug in directly before trying anything else.

Tap the three-dot menu mid-call and open Call Health. Packet loss above 2%, jitter above 30ms, or round-trip time above 200ms all point to a network problem.

Go to teams.microsoft.com and join a call from there. If the browser works and the desktop app doesn't, the issue is in the app, not your network.

VPNs route media through extra hops, which adds latency and causes drops. Disconnect and retest. If that fixes it, ask IT about split tunneling so Teams traffic bypasses the VPN.

Go to Settings > General and turn off hardware acceleration, then restart Teams. This resolves video rendering glitches on many machines.

This mode sends uncompressed audio and uses significantly more bandwidth. Disable it in Device Settings during a call if you do not need it.

Teams can behave unpredictably when IPv4 and IPv6 are both active on the same interface. Disable IPv6 in your network adapter properties and retest.

Disable power saving on your WiFi adapter, update the driver, and lock the connection to the 5 GHz band rather than letting the adapter switch bands automatically.

Go to connectivity.office.com and run the media quality check. The report shows exactly where latency or packet loss is occurring so you can pinpoint the cause.

Request split tunneling so Teams traffic routes directly rather than through the VPN tunnel. Ask IT to confirm that UDP ports 3478 to 3481 are not being proxied or deep-packet inspected, as this silently degrades media quality.

Teams uses WebSocket connections to deliver call notifications, signaling, and real-time updates. If a firewall or proxy is blocking WebSocket, Teams falls back to a slower HTTP method that adds latency and increases bandwidth usage. Ask IT to verify that WebSocket traffic to Microsoft 365 endpoints is permitted.

Teams media travels over UDP. If your firewall remaps the UDP source port or IP address mid-call (for example, due to a short NAT timeout), the call drops silently. Ask IT to confirm that NAT mappings are kept stable for the duration of a call and that the NAT pool has enough public IP addresses to avoid port exhaustion.

QoS marks Teams audio, video, and sharing packets so your network equipment prioritises them over general internet traffic. Without it, a large file download or backup on the same network can degrade a call without any obvious reason. Microsoft recommends QoS on all managed networks, even ones with adequate bandwidth, to protect call quality during unexpected network events.