Technical Tip: Microsoft Teams calls dropping

Description

This article describes that Microsoft Teams calls are dropping only behind FortiGate.

Scope

FortiGate.

Solution

• Users are having issues with Microsoft Teams calls dropping only behind FortiGate.

Check for LAN to WAN policy:

• Microsoft Teams uses UDP port 3478-3481 for communication.
• Add service with the same ports and UDP:

If still facing an Issue with Call Drops on a Specific ISP, take sniffer Packets for MS Teams:

diagnose sniffer packet any " src net 52.0.0.0/8 and portrange 3478-3481" 6 0 l

• Check the MSTeam traffic using which network subnet from Forward traffic, and set it to/8 subnet.
  Example: 52.0.0.0/8 is an MS-TEAM Subnet Network.

Note: Make sure the DOS policy is not dropping the packets, as Microsoft Teams uses UDP packets, which might be getting dropped by the UDP threshold configuration; therefore, lower the threshold value for the UDP traffic.

Related article:

Troubleshooting Tip: The most common issues with FortiGate and Microsoft Teams