How to Configure Teams Dial-In Audio Conferencing Bridges in PowerShell Using Set-CsOnlineDialInConferencingBridge

In Microsoft Teams enterprise voice and online meeting architectures, dial-in audio conferencing bridges serve as the central gateway connecting standard telephone callers to cloud-hosted meetings. When meeting organizers schedule online sessions, the conferencing bridge assigns local or toll-free telephone numbers, provides interactive voice response (IVR) prompts in multiple languages, validates meeting participant PINs, and plays entry and exit chimes. While per-user conferencing settings manage individual organizer PINs, tenant-level policies governing bridge security and announcement behavior are controlled at the bridge level.

Through the Microsoft Teams PowerShell module, administrators can programmatically manage their organization’s audio conferencing bridges using the Get-CsOnlineDialInConferencingBridge and Set-CsOnlineDialInConferencingBridge cmdlets. This allows administrators to adjust minimum organizer PIN lengths, customize entry and exit announcement formats, toggle anonymous toll-free dialing visibility, and assign primary default bridge service numbers across multi-region enterprise tenants. This guide covers how to inspect conferencing bridge configurations, adjust global bridge properties, and enforce meeting security standards.

Understanding Teams Audio Conferencing Bridge Architecture

A dial-in conferencing bridge represents a cluster of Microsoft-managed or partner-managed PSTN voice trunks connected to the Microsoft 365 cloud. The bridge configuration enforces several critical behavioral standards:

• DefaultServiceNumber: The primary geographic toll telephone number inserted into default meeting invitations for users who do not have an explicit regional override assigned.
• EnableEntryExitAnnouncements: Dictates whether the audio bridge plays a tone or announces participant names into the meeting audio channel when phone callers connect or disconnect.
• EntryExitAnnouncementsType: Specifies whether announcements take the form of an unobtrusive audio tone (Tone) or spoken recorded participant names (Name).
• ShowTollFreeNumberToAnonymousUsers: Controls whether anonymous or external participants accessing the online meeting join link can view toll-free dial-in numbers (useful for preventing unexpected telecom toll-free usage charges).
• Bridge PIN Length: Configures the minimum required character length for meeting organizer dial-in leader PINs across the organization (typically between 5 and 12 digits).

Connecting to Teams PowerShell and Inspecting the Active Bridge

To inspect your tenant’s conferencing bridge, launch an elevated PowerShell console and authenticate with Microsoft 365 credentials possessing the Teams Administrator role:

# Import the Teams PowerShell module and authenticate
Import-Module MicrosoftTeams
Connect-MicrosoftTeams

Execute Get-CsOnlineDialInConferencingBridge to retrieve the active conferencing bridge instance:

# Retrieve tenant conferencing bridge configuration
Get-CsOnlineDialInConferencingBridge

The resulting object displays the bridge parameters:

Identity                           : Dial-In Conferencing Bridge
Name                               : Dial-In Conferencing Bridge
DefaultServiceNumber               : +442038555123
EnableEntryExitAnnouncements       : True
EntryExitAnnouncementsType         : Tone
ShowTollFreeNumberToAnonymousUsers : False
PinLength                          : 6
Region                             : Europe

Setting the Default Organization Bridge Service Number

When organizations change primary corporate headquarters or port existing corporate telephone ranges into Microsoft 365, the default bridge telephone number must be updated so newly scheduled meetings reflect the correct dial-in number.

First, list all verified conferencing bridge service numbers assigned to your tenant:

# Query all active toll and toll-free conferencing service numbers
Get-CsOnlineDialInConferencingServiceNumber | 
    Select-Object Number, City, CountryOrRegion, BridgeName

Then, update the primary bridge service number using Set-CsOnlineDialInConferencingBridge:

# Update the default primary bridge service number
Set-CsOnlineDialInConferencingBridge -Name "Dial-In Conferencing Bridge" `
    -DefaultServiceNumber "+442038555999"

Configuring Entry and Exit Announcement Policies

Participant arrival chimes help meeting leaders track attendance. However, in large corporate webinars or all-hands presentations, loud name announcements or chimes disrupt presenters. You can configure global defaults at the bridge level:

Switching to Unobtrusive Chimes (Tones)

To ensure audio alerts remain subtle without spoken name interruptions:

# Configure bridge to play subtle audio tones on join/leave
Set-CsOnlineDialInConferencingBridge -Name "Dial-In Conferencing Bridge" `
    -EnableEntryExitAnnouncements $True `
    -EntryExitAnnouncementsType Tone

Disabling Announcements Entirely

For silent join experiences across all tenant meetings:

# Disable all entry and exit audio chimes globally
Set-CsOnlineDialInConferencingBridge -Name "Dial-In Conferencing Bridge" `
    -EnableEntryExitAnnouncements $False

Restricting Toll-Free Dialing for Anonymous Users

Toll-free numbers incur per-minute usage billing charged against your organization’s Communications Credits. To prevent unauthorized or anonymous attendees from running up toll-free charges when they could easily use local toll numbers or the free Teams web/mobile app, disable toll-free visibility for anonymous participants:

# Hide toll-free dial-in numbers from anonymous attendees
Set-CsOnlineDialInConferencingBridge -Name "Dial-In Conferencing Bridge" `
    -ShowTollFreeNumberToAnonymousUsers $False

When this setting is $False, the web-based meeting join page displays only standard local toll dial-in numbers to unauthenticated external guests.

Auditing and Enforcing Secure PIN Lengths

Meeting organizers use dial-in PINs to authenticate as meeting leaders over the phone, start meetings without computer hosts, and unlock the meeting lobby. To protect against brute-force attacks, verify that the bridge enforces a strong PIN length (e.g., 6 to 8 digits):

# Verify current organizer PIN length policy
(Get-CsOnlineDialInConferencingBridge).PinLength

While PIN length is primarily configured during initial tenant tenant provisioning, ensuring organizers maintain multi-digit PINs protects against unauthorized conference hijacking.

Troubleshooting Common Audio Conferencing Bridge Issues

When administering Teams conferencing bridges, keep these diagnostic factors in mind:

• Service Number Assignment Restrictions: You cannot assign an arbitrary phone number as the DefaultServiceNumber. The telephone number must be actively acquired as a Service Number (not a standard user subscriber number) and assigned to the Audio Conferencing bridge resource inside the Teams Admin Centre or via Set-CsPhoneNumberAssignment.
• Global Replication Delays: When updating bridge properties—such as changing announcement tones or updating default service numbers—allow up to 2 to 4 hours for the new configuration to replicate across Microsoft’s global PSTN edge clusters. Existing active meetings will not reflect the changes until a new meeting session begins.
• Conflict with Per-User Overrides: If an individual meeting organizer has a custom announcement setting configured via Set-CsOnlineDialInConferencingUser, their personal user profile takes precedence over the global bridge default. Always audit both user and bridge settings when troubleshooting inconsistent announcement behavior.

Using Set-CsOnlineDialInConferencingBridge enables administrators to enforce enterprise-grade security, reduce unnecessary telecom costs, and ensure a professional audio experience across all Microsoft Teams phone conferences.