Free MS-721 Practice Questions with Detailed Explanations

Test your Collaboration Communications Systems Engineer readiness with 15 free scenario-based questions covering Direct Routing, voice routing, auto attendants, emergency calling, and Teams Rooms.

18 min readUpdated May 2026MS-721 Associate

MS-721 is one of the more technically demanding Microsoft 365 Associate exams — Direct Routing, voice routing regex, emergency calling configuration, and Teams Rooms operating modes all show up at depth. These 15 questions mirror the real exam's format and difficulty.

What you'll get:

  • 15 scenario-based questions across all 4 MS-721 domains
  • Real exam difficulty — Direct Routing SBC config, voice routing regex, LBR, emergency calling, Teams Rooms
  • Detailed explanations for every answer
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PSTN Strategy + Configure Teams Phone

Questions 1–9

1
PSTN Connectivity Selection

Your organization operates in 30 countries with existing carrier contracts that you must preserve. You want centralized control over voice routing policies and the ability to deploy your own SBCs in each region.

Which PSTN connectivity option fits best?

  1. A.Microsoft Calling Plans across all 30 countries
  2. B.Operator Connect with multiple operators
  3. C.Direct Routing with regional SBCs in each major region
  4. D.Teams Phone Mobile across all users

Correct: C. Direct Routing lets you preserve existing carrier contracts and deploy your own SBCs for centralized control of voice routing. Calling Plans replace your carrier relationship entirely. Operator Connect requires using certified Operator Connect carriers (which may not match your existing carrier set). Teams Phone Mobile is SIM-based and inappropriate for a multi-country enterprise replacement of all telephony.

2
SBC Certificate Requirements

You are pairing a new AudioCodes SBC with Microsoft Teams Direct Routing. The SBC FQDN is sbc.contoso.com. Pairing fails during OPTIONS pings.

Which is the most likely cause?

  1. A.The SBC certificate is from a self-signed CA
  2. B.The SBC certificate is valid but does not include sbc.contoso.com in the Subject Alternative Name
  3. C.TCP port 5060 is not open on the SBC
  4. D.The Teams tenant has not registered the SBC in the Azure portal

Correct: B. The SBC certificate must include the SBC FQDN (sbc.contoso.com) in the Subject Alternative Name (SAN). A missing SAN entry is the most common cause of OPTIONS ping failure even when the certificate is from a trusted CA. Self-signed certificates would also fail but the question presumes a real CA. Direct Routing uses TLS 5061, not TCP 5060. SBC pairing happens via Set-CsOnlinePSTNGateway in PowerShell, not the Azure portal.

3
Voice Route Regex

You need a voice route that matches any UK mobile number — UK mobile numbers start with +447 followed by 9 digits.

Which regex pattern matches correctly?

  1. A.+447.*
  2. B.^\+447\d{9}$
  3. C.\+447\d{1,15}
  4. D.+447[0-9]+

Correct: B. ^\+447\d{9}$ uses regex anchors to require a match against the full number, the literal +447 prefix, and exactly 9 trailing digits — the precise UK mobile pattern. The other options either miss the anchors (matching unintended numbers), allow too many or too few digits, or fail to escape the + character.

4
Voice Routing Policy Structure

You need to allow Sales users to dial UK and US numbers but block all other international destinations, while routing UK calls through SBC-EU and US calls through SBC-US.

How do you configure this?

  1. A.Two separate voice routing policies, one for UK and one for US, assigned to Sales users
  2. B.A single voice routing policy containing two PSTN usages: "UK Calls" (route with +44\d+ pattern to SBC-EU) and "US Calls" (route with +1\d+ pattern to SBC-US), assigned to Sales users
  3. C.Two dial plans normalizing UK and US numbers separately
  4. D.Conditional Access policies blocking non-UK/US destinations

Correct: B. A single voice routing policy contains multiple PSTN usages, each with its own voice routes and target SBCs. Including UK and US PSTN usages (but no others) implicitly blocks other destinations because no matching voice route exists. A single policy is easier to manage than two. Dial plans normalize numbers but do not select SBCs. Conditional Access controls authentication, not voice routing.

5
Auto Attendant Holiday Override

Your auto attendant has business hours Mon-Fri 9 AM-5 PM playing "Business hours greeting" and otherwise "After hours greeting". You configure Thanksgiving (a Thursday) as a holiday with a "Holiday greeting". On Thanksgiving at 10 AM, what plays?

Which greeting plays?

  1. A.Business hours greeting
  2. B.After hours greeting
  3. C.Holiday greeting
  4. D.Both holiday and business hours greetings concatenated

Correct: C. Holiday schedules override business hours in Teams auto attendants. On a configured holiday, the holiday greeting plays regardless of the time of day. A common MS-721 trap — Microsoft's order of evaluation is holiday first, then business hours.

6
Call Queue Routing

A 10-person support call queue must distribute calls evenly across all agents over time, but on each call only one agent rings at a time.

Which routing method fits?

  1. A.Attendant
  2. B.Serial
  3. C.Longest idle
  4. D.Round robin

Correct: D. Round robin rotates calls evenly across agents in turn — agent 1 takes the first call, agent 2 the second, etc., wrapping around. Attendant rings everyone at once. Serial rings agents in a configured order, always starting from the first. Longest idle picks the agent idle longest, which may not be even over short windows.

7
Emergency Call Routing for Direct Routing

Your Direct Routing deployment requires that emergency calls (911 in the US) route through SBC-EMERGENCY to reach the correct PSAP, while non-emergency calls route through SBC-US.

Which policy configures this?

  1. A.CsTeamsEmergencyCallingPolicy with NotificationMode = Conferenced
  2. B.CsTeamsEmergencyCallRoutingPolicy with emergency dial string 911 mapped to a PSTN usage targeting SBC-EMERGENCY
  3. C.CsOnlineVoiceRoutingPolicy with a higher-priority 911 voice route
  4. D.CsTeamsCallingPolicy with AllowEmergencyCalls enabled

Correct: B. Emergency Call Routing Policy is Direct Routing-specific and contains emergency dial strings mapped to PSTN usage records — exactly the mechanism for routing 911 through a dedicated emergency SBC. Emergency Calling Policy handles notifications (security desk alerts) but not gateway selection. A normal voice routing policy does not have the emergency-specific behavior (override standard routing on dial string match). Teams Calling Policy controls calling features, not emergency routing.

8
Location-Based Routing

A multinational company has offices in India where regulations prohibit toll bypass — calls must terminate on the local Indian PSTN gateway, not via international SBCs. Users in other countries are not affected.

What must you configure to enforce this?

  1. A.A separate Teams tenant for India
  2. B.Tenant Network Sites with the India office's subnets, then a voice routing policy with Location-Based Routing enabled, assigned to India users
  3. C.A Conditional Access policy blocking international calls
  4. D.A DLP policy detecting international numbers

Correct: B. Location-Based Routing (LBR) requires tenant Network Sites that map subnets to physical locations, plus voice routing policies marked for LBR and assigned to users. When an LBR-enabled user attempts an international call from an India subnet, the call is forced through the local Indian gateway. Separate tenants would work but is operationally extreme. Conditional Access does not control voice routing. DLP does not affect calls.

9
Media Bypass

You want media to flow directly between the Teams client and the SBC, bypassing Microsoft's media relays, to reduce latency for an internal call between two employees in the same building.

Which capability provides this?

  1. A.Direct Routing without any additional configuration
  2. B.Enable Media Bypass on the Direct Routing SBC (Set-CsOnlinePSTNGateway -MediaBypass $true), provided client IP can reach SBC IP
  3. C.Enable Audio Conferencing for both users
  4. D.Operator Connect with media bypass enabled by the carrier

Correct: B. Media Bypass is configured per SBC with Set-CsOnlinePSTNGateway -MediaBypass $true and requires that the Teams client can reach the SBC IP directly (no NAT or firewall blocking media). Standard Direct Routing routes media via Microsoft's media relays. Audio Conferencing is unrelated. Operator Connect uses the operator's infrastructure differently than Direct Routing.

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Teams Rooms and Devices

Questions 10–13

10
Teams Rooms OS Selection

You are deploying 50 new Teams Rooms across small huddle rooms with limited IT support staff. You prefer a simple OEM-managed update model and a lower-cost device option.

Which Teams Rooms operating mode is most appropriate?

  1. A.Teams Rooms on Windows with Windows IoT Enterprise
  2. B.Teams Rooms on Android (AOSP — Android Open Source Project)
  3. C.Surface Hub 2S
  4. D.Microsoft Teams Web App on a generic PC

Correct: B. Teams Rooms on AOSP Android offers a simpler OEM-managed update model and lower-cost certified devices ideal for huddle rooms — exactly the scenario fit. Teams Rooms on Windows is more capable but requires Windows admin skills. Surface Hub 2S is a premium single-device experience inappropriate for "50 huddle rooms". Teams Web App on generic PCs is not a certified Rooms experience.

11
Resource Account

You are deploying a Teams Room and need to give it an identity to receive meeting invitations and sign in as the room.

What do you configure?

  1. A.A regular Microsoft 365 user account
  2. B.A shared mailbox with a Teams Rooms Pro or Basic license
  3. C.A Microsoft Teams Phone Resource Account license only
  4. D.A managed identity in Microsoft Entra ID

Correct: B. Teams Rooms requires a resource account that is typically a shared (or room) mailbox in Exchange Online, assigned a Teams Rooms Pro or Basic license. The license enables the room to sign in to Teams and use the Rooms experience. Regular user accounts work but are over-licensed (a full M365 license costs more). Teams Phone Resource Account licenses are for auto attendants and call queues, not for rooms. Managed identities are for Azure resource access.

12
Pro Management Portal

You manage 200 Teams Rooms across 20 sites and want centralized device inventory, peripheral health monitoring (cameras, microphones), incident detection, and remote firmware management.

Which capability provides this?

  1. A.Microsoft Intune device compliance reports
  2. B.The Teams Rooms Pro Management portal
  3. C.Microsoft Endpoint Manager configuration profiles
  4. D.Per-device management via the device's local web UI

Correct: B. The Pro Management portal is the dedicated management surface for Teams Rooms Pro-licensed devices, providing inventory, peripheral health, incident detection, remediation, and firmware management at scale. Intune compliance reports are general device compliance, not Teams-Rooms-specific. Endpoint Manager configuration profiles can deploy settings but lack the Rooms-specific peripheral monitoring. Local web UIs do not scale to 200 devices.

13
SIP Gateway

You have 100 existing Cisco SIP desk phones that you want to keep in production while migrating to Teams Phone. The phones should authenticate against your Teams tenant and provide basic dialing.

Which Microsoft capability enables this?

  1. A.Direct Routing — pair the phones as SBCs
  2. B.Microsoft Teams SIP Gateway — third-party SIP phones authenticate via the SIP Gateway service
  3. C.Operator Connect — the operator manages the phones
  4. D.Replace all 100 phones with Microsoft Teams-certified IP phones

Correct: B. SIP Gateway is the Microsoft service that lets third-party SIP phones (Cisco, Yealink, Poly, etc.) authenticate to Teams and place basic calls — exactly the migration scenario. Direct Routing is for carrier connectivity, not endpoint phones. Operator Connect is for PSTN connectivity. Replacing all phones is costly and unnecessary for the bridging period.

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Meetings, Webinars, Town Halls

Questions 14–15

14
Town Halls vs. Webinars

Your CEO will deliver a quarterly update to 8,000 employees. You need RTMP-in support to use a professional hardware encoder for video quality, and a green room for executives to prepare before going live.

Which Teams meeting type fits?

  1. A.Regular Teams meeting
  2. B.Teams webinar
  3. C.Teams town hall
  4. D.Live event (legacy)

Correct: C. Teams town halls support large audiences (10,000+), RTMP-in for hardware encoder integration, RTMP-out for distribution, and a green room for presenter preparation — exactly the executive broadcast scenario. Webinars top out around 1,000–2,000 attendees with no RTMP-in. Regular meetings are too small. Live events are being deprecated in favor of town halls.

15
Compliance Recording

Your financial-services organization must record all employee voice calls for regulatory compliance and retain the recordings for 7 years in a third-party archive. The current call platform must remain Teams Phone (Calling Plans).

How do you implement this?

  1. A.Enable Teams meeting recording for all users
  2. B.Integrate a Microsoft-certified compliance recording provider (Mida, Verba, ASC) with Teams Phone Standard, which intercepts calls for recording
  3. C.Use Microsoft Purview retention policies on Teams content
  4. D.Manually export call detail records from the Teams admin center

Correct: B. Microsoft-certified compliance recording providers (Mida, Verba, ASC, NICE, etc.) integrate with Teams Phone via the Teams Phone Standard compliance recording API to intercept and record voice calls for regulatory archiving. Teams meeting recording records meetings, not 1:1 PSTN calls. Purview retention applies to content, not real-time call audio. Manual CDR export gives metadata, not recordings.

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