2 SSTP clients: No ringing while starting a call within Microsoft Teams

Chris4711CD 21 Reputation points


so we have 2 clients:

  • client A connects to a VPN server vpn.mydomain.com (Windows server 2019 with SSTP and IPv4 only)
  • client B connects to the same server, i.e. vpn.mydomain.com with SSTP


  • client A wants to call client B within Microsoft Teams. A sceen shows up and it is ringing.
  • client B doesn´t see anything. There´s no ringing.


  • client A stops calling client B
  • Now client B sees a missing call from client A

It doesn´t matter which client, as long of one of the clients is connected to the VPN server vpn.mydomain.com and the other client is not connected to the same VPN server, the call works without any problems. If both clients are connected concurrently it fails.

Has anyone ever had such a problem?

Kind Regards

Microsoft Teams
Microsoft Teams
A Microsoft customizable chat-based workspace.
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Accepted answer
  1. JimmyYang-MSFT 50,446 Reputation points Microsoft Vendor

    Hi @Chris4711CD ,

    Do you mean the receiver cannot see any windows notification in Microsoft Teams?

    Do you have the same issue in Teams web client?

    According to your description, it seems related to your network environment. It recommends you provide an alternate path for Teams traffic that bypasses the virtual private network (VPN). For more details about it, you can refer to:


    In addition, please try to sign out Teams client and clear cache file to see if it works for you.

    If the response is helpful, please click "Accept Answer" and upvote it.

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

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