Guides / Teams video calls freezing: outage or network?
Updated 3 Oct 2026
Teams video calls freezing: outage or network?
How to tell a Teams outage from packet loss, proxy hairpins, and a congested office circuit.
Chat is fine. The calendar is fine. Two minutes into the stand-up the video tiles freeze and voices turn into a modem. That is not the same incident as "Teams is down".
If it is actually Teams
A real Teams outage takes out sign-in, chat, or meeting join for a lot of tenants at once. Check the Teams status page. If Microsoft has not posted, and only your office is suffering, you are holding a network ticket.
The media path
Teams chat is HTTPS. Teams calls want UDP 3478–3481 to Microsoft's relay, plus a pile of secondary ports. A firewall that "allows Teams" on 443 only will give you exactly this symptom: chat lives, calls die.
The other classic is a VPN that hairpins media through another country. Split-tunnel the Teams media ranges. If you cannot, take the call on the phone app on LTE. If LTE is crystal and the office Wi-Fi is soup, stop blaming Microsoft.
What an engineer actually checks
- Same user, mobile app, leave the building Wi-Fi. Better? It is the office path.
- Call analytics in the Teams admin centre: packet loss and jitter for that call. Those numbers are the argument. Opinions are not.
- Access point count vs people on the call. One domestic mesh node in a 30-person meeting room will freeze every Friday.
- Quality of Service markings getting stripped by the cheap switch you have been meaning to replace.
What to tell the user
"Teams itself is up. Your call is losing packets on the office network. Join from your phone this time; we will fix the access point after the meeting."