Microsoft Teams direct Routing SBC connection Issue

Question

Hi,

Currently I have configured the SBC and opened the needed firewall ports and allowed the required IP addresses on our side.
However, I can see from our SBC that there is always a Remote closure when an OPTIONS Ping is sent from our SBC.
Looking at the firewall logs, I can see that the SIP packets are correctly sent to the Msft Teams but Teams complains that they have issue connecting to the SBC.

TCP TLS Handshake is OK and active on the Teams side as well.

Can you provide more info on this?

Attached are some information from our SBC and Firewall.

![45346-image.png][3]

1: /api/attachments/45429-image.png?platform=QnA [3]: /api/attachments/45346-image.png?platform=QnA

Answer 1

Hi @James ,

Does anyone else have the same issue in your organization?

Are there any error messages from SBC’s SIP logs?

In my experience, you need to configure TeamsUpgradePolicy to ensure incoming calls are received in Teams. User must be in TeamsOnly Mode. For more details about setting:

https://techcommunity.microsoft.com/t5/microsoft-teams/move-some-users-to-quot-teams-only-quot-mode-with-powershell/m-p/848814

---

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.