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Teams Call Quality Troubleshooting Checklist

Teams Call Quality Troubleshooting Checklist

Work through these steps in order. Most Teams audio and video problems are solved before you reach the bottom, and the last four are the ones to hand to IT.

MStack360 Team

Jul 4, 20263 min read

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2 sections

Try yourself first
Escalate to IT

IN 30 SECONDSFull read: 3 min

Test on wired Ethernet first: it rules out WiFi interference and packet loss in one step.
Packet loss above 2%, jitter above 30ms or round-trip above 200ms point to the network.
VPN split tunnelling, open UDP 3478 to 3481, stable NAT and QoS are IT's part.

Work through these steps in order. Most Teams audio and video problems are solved before you reach the bottom. Tick each one off as you go.

Try yourself first#

Try yourself first

0 of 9 done

Test on a wired Ethernet connection (quick win)Rules out WiFi interference and packet loss in one step. Plug in directly before trying anything else.
Check call health during a callTap 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.
Try Teams in the browserGo 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.
Turn off your VPN for the callVPNs 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.
Disable GPU hardware acceleration in TeamsGo to Settings > General and turn off hardware acceleration, then restart Teams. This resolves video rendering glitches on many machines.
Turn off High Fidelity Music ModeThis mode sends uncompressed audio and uses significantly more bandwidth. Disable it in Device Settings during a call if you do not need it.
Disable IPv6 on your WiFi adapterTeams can behave unpredictably when IPv4 and IPv6 are both active on the same interface. Disable IPv6 in your network adapter properties and retest.
Tune your WiFi connectionDisable 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.
Run the Microsoft connectivity testGo 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.

Escalate to IT#

IT actions

0 of 4 done

Enable VPN split tunneling and check UDP portsRequest 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.
Confirm WebSocket connections are not blockedTeams 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.
Check that the firewall preserves NAT session stateTeams 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.
Implement Quality of Service (QoS) for Teams trafficQoS 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.

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WRITTEN BY

MStack360 Team

The MStack360 team delivers Microsoft 365 migrations, security and Power Platform projects for businesses across North America, Europe, Australia and the Middle East.

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