MS-721 Practice Test

Sample MS-721 Practice Questions

10 real questions from the free MS-721bank. Pick an answer in your head, then open “Show answer” for the explanation.

1. 1. An organization is preparing its network for a Direct Routing SBC deployment. The network team asks what public network requirements the SBC must meet to establish connectivity with Microsoft Teams Phone infrastructure. Which requirement is mandatory?

   • A. The SBC must connect to Microsoft via a site-to-site IPsec VPN tunnel
   • B. The SBC must have a private MPLS connection to the nearest Microsoft Azure region
   • C. The SBC must be assigned to the Microsoft 365 trusted IP address list
   • D. The SBC must have a publicly routable IP address and a fully qualified domain name (FQDN) resolvable in public DNS
   Show answer

   Correct answer: D

   Microsoft Teams Direct Routing requires SBCs to have a publicly routable IP address and an FQDN that resolves in public DNS. Microsoft's Teams Phone infrastructure connects to the SBC over the public internet using mutual TLS (mTLS) and SRTP. SBCs behind NAT are supported in specific scenarios but must still present a public identity.

2. 2. A telecommunications director at a manufacturing company needs PSTN connectivity for Teams Phone. The company has a contract with a local carrier not available through Operator Connect, requires call survivability at branch offices that experience periodic internet outages, and wants to retain existing on-premises telephony infrastructure. Which solution should be recommended?

   • A. Microsoft Calling Plan with Teams Phone Mobile as a fallback
   • B. Direct Routing with a certified SBC and Survivable Branch Appliances (SBAs)
   • C. Operator Connect with a backup SBC configuration
   • D. Shared Calling with a local PSTN gateway
   Show answer

   Correct answer: B

   Direct Routing allows integration with any SIP-compliant carrier, including carriers not available in the Operator Connect marketplace. Pairing it with Survivable Branch Appliances (SBAs) provides basic calling functionality when the branch office loses connectivity to the Microsoft Teams infrastructure, satisfying both requirements.

3. 3. A company is deploying Teams Rooms in a large executive boardroom that has an existing Crestron room control system, requires integration with a PTZ camera controller, needs multiple simultaneous content sources, and has complex audio system requirements with distributed speakers. Which Teams Rooms platform best supports this level of AV complexity?

   • A. Teams Rooms on Android with a certified touchpanel controller
   • B. Teams Rooms on Windows
   • C. Teams Rooms on Surface Hub 2S
   • D. BYOD configuration with a dedicated Teams room account
   Show answer

   Correct answer: B

   Teams Rooms on Windows supports advanced AV integrations, custom XML-based configuration, third-party room control system integration, and complex peripherals. It is the preferred platform for large rooms with sophisticated AV requirements, custom hardware configurations, and environments where IT teams need granular control over the room system.

4. 4. A manufacturing plant has 80 Teams Phone users. The facility experiences internet outages of 3-6 hours several times per month due to line maintenance. During outages, workers must still be able to make and receive basic PSTN calls. Which solution provides call continuity during these outages?

   • A. Survivable Branch Appliance (SBA)
   • B. Teams Phone Mobile with a participating carrier as backup
   • C. Local Direct Routing SBC without Microsoft cloud dependency
   • D. Microsoft Calling Plan with offline call cache
   Show answer

   Correct answer: A

   Survivable Branch Appliances (SBAs) are certified on-premises devices that maintain a local Teams Phone proxy when connectivity to Microsoft's cloud infrastructure is unavailable. Users registered to an SBA can continue making and receiving basic PSTN calls during internet outages, providing the branch call survivability required.

5. 5. A company wants to ensure Teams voice calls receive network priority over regular web browsing and file downloads. Which marking mechanism does Microsoft recommend for Teams traffic to enable Quality of Service prioritization on the network?

   • A. VLAN tagging with voice VLAN assignment
   • B. IP SLA probes for traffic classification
   • C. TCP window size adjustment for voice streams
   • D. DSCP (Differentiated Services Code Point) markings
   Show answer

   Correct answer: D

   Microsoft Teams uses DSCP markings to identify and prioritize different traffic types: EF (46) for audio, AF41 (34) for video, and AF21 (18) for screen sharing and data. Network devices then use these DSCP values to apply QoS policies and prioritize voice traffic over lower-priority traffic.