You have a Microsoft Teams Phone deployment You use Direct Routing with a Survivable Branch Appliance (SBA) at a site. The site experiences an extended internet outage. Which three PSTN calling…

Question

Options

• Adynamic emergency calling
• Boutbound PSTN calls
• Cinbound PSTN calls
• Dcall transfer of PSTN calls
• Ehold and resume of PSTN calls

• A
  20% (6)
• B
  70% (21)
• D
  10% (3)

Explanation

During an internet outage, the Survivable Branch Appliance (SBA) maintains a direct local connection to the Session Border Controller (SBC), allowing it to handle basic PSTN call flow independently of Microsoft 365 cloud services. This means outbound PSTN calls (B) can be placed through the local SBC, inbound PSTN calls (C) can be received and routed to registered Teams clients, and hold/resume (E) functions are supported as basic call-control signaling is handled locally by the SBA without needing cloud connectivity.

Dynamic emergency calling (A) is incorrect because it relies on Microsoft's cloud services to dynamically determine a user's physical location - that cloud lookup is unavailable during an outage. Call transfer (D) is incorrect because transferring a PSTN call requires re-routing signaling through Microsoft's Teams infrastructure in the cloud, which the SBA cannot do on its own.

Memory tip: Think of the SBA as a "bare minimum lifeline" - it keeps calls flowing in and out and lets you pause them, but anything requiring a cloud decision (Where is this user? Where should this call go next?) fails. If the feature needs Microsoft 365 to "think," it won't work during an outage.

No community discussion yet for this question.