01 · Foundations
A license on a user who is still homed on a legacy registrar will not produce Direct Routing calls.
Direct Routing expects the user to be homed in Microsoft 365. Islands mode is explicitly unsupported for Direct Routing. Those are registrar and coexistence facts, not SBC opinions.
Read the user before you assign a voice routing policy. If the pilot group is a mix of online users and leftover coexistence modes, you will debug one trunk twice and learn nothing.
Check that the user is homed online and not in Islands mode before you touch the SBC.
Direct Routing users are homed online, and they are not in Islands mode.
If it fails: Half the pilot works. The other half is still in a coexistence mode the plan page excludes.
A colleague reports: Callers hear a greeting failure and the SBC trace is clean. Where do you start?
Callers hear a greeting failure and the SBC trace is clean. Confirm the mailbox and the voicemail policy before you debug the SBC. Source: https://learn.microsoft.com/en-us/microsoftteams/cloud-voicemail accessed 2026-10-14.
Which description of Conditional Access is accurate?
Entra policy that can block a phone or a room that is not in the trusted device set. Voice engineers see a SIP 200 and a device that never registers. Source: https://learn.microsoft.com/en-us/credentials/certifications/security-compliance-and-identity-fundamentals/ accessed 2026-10-14.
A colleague reports: Rooms fail on Monday after a security change nobody told voice about. Where do you start?
Rooms fail on Monday after a security change nobody told voice about. Exclude or scope device sign-in on purpose. Do not turn Conditional Access off as a test you leave in place. Source: https://learn.microsoft.com/en-us/credentials/certifications/security-compliance-and-identity-fundamentals/ accessed 2026-10-14.
Around the call: compliance recording, workforce management, emergency location, analytics, CRM screen pop, and an agent with a human escape. Each one has its own failure.
Half the pilot works. The other half is still in a coexistence mode the plan page excludes.
Cisco CUBE is one of the SBC families named in this lab’s certification lesson. A certified release can be the Direct Routing SBC between Unified CM and Teams.
The tenant still needs a verified domain on the SBC FQDN, and the user still needs Teams Phone. The studio translator does not open a live AXL session. Confirm the current certified release before you build.
Teams Phone and Webex Calling are separate clouds. This lab does not describe a feature that registers a Webex Calling user into a Teams tenant.
A number move is usually a carrier port, a certified SBC, or a meetings interop product. Confirm before relying.
Unified CCE stays the ACD until you migrate it. Microsoft’s contact-center articles name Connect, Extend, and Unify. They do not name a UCCE connector in the notes this lab cites.
Voice into Teams is still Direct Routing or Operator Connect. The routing script stays on the contact-center product you bought. Confirm the vendor’s current model. Source: https://learn.microsoft.com/en-us/microsoftteams/teams-contact-center.
Copilot Studio, Azure Communication Services, and Graph are later tracks in this lab. Treat any uncited limit as confirm before relying.
Opened 2026-10. A row marked confirm did not open. Wikipedia is background. The Teams blog row is the community index.
