Teams Calls Dropping or Poor Quality? How to Fix It

You're mid-pitch and your voice turns robotic. Video freezes, people say you've cut out, and Teams shows a banner: "Your network quality may be affecting call quality" or "Poor network quality". Sometimes the call drops altogether with "Reconnecting…", or other people sound like they're underwater.

Poor Teams call quality is one of the most frustrating everyday IT problems, because it happens in front of clients. It's usually down to the network, and occasionally the headset, the PC or the Teams app itself. Here's how to narrow it down.

Why This Happens

Teams calls are real-time. Unlike downloading a file, Teams can't wait for lost data to arrive again, so small network problems show up as glitches. The main culprits are:

• Wi-Fi. Weak signal, interference, busy networks and roaming between access points cause packet loss and jitter.
• Upload speed. Many office and home broadband connections have far less upload than download.
• VPNs. Sending Teams traffic through a VPN adds delay and often bottlenecks.
• Competing traffic. Cloud backups, OneDrive syncing large files or someone streaming video.
• The device. An overloaded laptop, outdated drivers or a poor headset.

Fix 1: Check Call Health During a Call

Teams has built-in diagnostics. During a call, look under the More (…) menu for Call health (the location has moved between versions, so it may sit under Settings). It shows your network's round-trip time, packet loss and jitter, plus audio, video and screen sharing stats.

• High packet loss or jitter points to Wi-Fi or your connection.
• High round-trip time suggests a VPN, a congested line or a long route to Microsoft.
• Good network figures but poor quality points at your device, headset or the other person's connection.

Fix 2: Fix the Network

1. Use a cable where you can. A wired connection removes most Wi-Fi problems at a stroke, and a USB-C to Ethernet adapter is cheap.
2. On Wi-Fi, use 5GHz and sit closer to the access point. Avoid calls while walking between rooms.
3. Disconnect the VPN for Teams calls, unless your admin has told you otherwise.
4. Pause heavy traffic. Pause OneDrive sync, stop large uploads and ask others not to stream during important calls.
5. Test your connection with Microsoft's network connectivity test at connectivity.office.com, which checks the route to Microsoft 365 rather than just raw speed.

Fix 3: Check Your Headset and Devices

• In Teams, go to Settings > Devices and make sure the correct speaker, microphone and camera are selected. Make a test call from the same screen.
• Bluetooth headsets can switch to a lower-quality mode when the microphone is active, and drop out at range. A wired or USB dongle headset, ideally certified for Teams, is more reliable.
• Close unnecessary apps and browser tabs. Check Task Manager for CPU at 100%.
• Update graphics, audio and network drivers through Windows Update or the manufacturer's tool.

Fix 4: Update or Repair Teams

Make sure you're using the new Teams app, as classic Teams has been retired. Click the three dots next to your profile picture and choose Check for updates if available. If calls fail completely, or audio devices don't appear, try clearing the cache using our guide to clearing the Teams cache.

For Your Microsoft 365 Admin

• Per-user call analytics. In the Teams admin centre, go to Users > Manage users, select the user and look for Meetings & calls or call history. Each call shows network, device and quality details for each participant, which tells you whose connection was the problem.
• Call Quality Dashboard (CQD). At cqd.teams.microsoft.com you can see trends across the organisation. Uploading building and subnet data makes it far more useful, letting you spot a problem office or Wi-Fi network.
• VPN split tunnelling. Microsoft recommends sending Teams media traffic directly to the internet rather than through the VPN. Configure the VPN client to exclude Microsoft's published Teams IP ranges.
• Firewall. Allow outbound UDP 3478 to 3481 to Microsoft's Teams media ranges. If UDP is blocked, Teams falls back to TCP, which degrades quality.
• Quality of Service (QoS). On managed networks, tag Teams traffic so routers prioritise it. Teams uses default source port ranges for audio, video and screen sharing that can be used for tagging.
• Bandwidth. Check the office's upload capacity against the number of simultaneous video calls. Microsoft's bandwidth guidance for Teams gives figures per call type.

How to Stop It Happening Again

Most offices with poor Teams calls have Wi-Fi designed for email, not real-time video: consumer routers, too few access points, no prioritisation and a broadband line with weak upload. A properly planned network with business-grade access points, a decent upload, QoS and sensible VPN configuration fixes call quality for everyone. Standard headsets and up-to-date, managed laptops remove the rest.

When to Call in Help

If call problems affect the whole office, or happen to people working from home with good connections, it's worth a proper investigation. Our IT support team can review call analytics and your network, and our managed IT service keeps networks, devices and Teams in good shape. For telephony, see our Teams Phone service. Get in touch.

Related Reading

• How to Clear the Teams Cache
• Outlook Disconnected or Trying to Connect? Fix It
• Microsoft 365 Setup Guide for Small Teams