What is a possible cause of the issue?

You have a Microsoft Teams Phone deployment.

You are deploying Direct Routing by using a certified Session Border ControNer CSBC).

The FQDN of the SBC is sbc1.contoso.com. You use signaling port 5067.

You cannot place calls and receive an error message in the Microsoft Teams admin center as shown in the following exhibit.

What is a possible cause of the issue?
A . The firewall blocks traffic on pan 5067
B . Location-Based Routing is enabled for the SB
D . Calling plan licenses are not assigned to users.
E . The SIP options are disabled.

Answer: A

Explanation:

Reference: https://docs.microsoft.com/en-us/microsoftteams/troubleshoot/phone-system/direct-routing/sip-options-tls-certificate-issues