How to Configure Teams Phone Network Inter-Region Links in PowerShell Using CsTenantNetworkInterRegionLink

In global enterprise voice architectures powered by Microsoft Teams Phone, corporate WAN connections link regional headquarters, datacentres, and branch offices across continents. When users initiate voice calls or video conferences that cross regional network boundaries, unpredictable bandwidth fluctuations and WAN congestion can degrade audio quality. To manage wide area network traffic and enforce voice routing governance, Microsoft Teams provides Network Inter-Region Links. These logical constructs interconnect pairs of defined Network Regions and associate bandwidth policies for Call Admission Control (CAC) and Location-Based Routing (LBR). Using the Microsoft Teams PowerShell module, voice administrators can deploy, manage, and audit inter-region links with cmdlets such as New-CsTenantNetworkInterRegionLink, Set-CsTenantNetworkInterRegionLink, and Get-CsTenantNetworkInterRegionLink.

Role of Inter-Region Links in Teams Call Admission Control (CAC)

The Microsoft Teams enterprise voice network topology organizes infrastructure hierarchically into Network Regions, Network Sites, and Subnets. When media streams travel between two distinct geographic regions, Microsoft Teams evaluates the Inter-Region Link connecting them:

• Bandwidth Constraint Enforcement: Limits the aggregate bandwidth that real-time audio and video sessions can consume across the interconnecting WAN pipe. When bandwidth thresholds are reached, CAC prevents additional sessions from degrading existing calls.
• Alternate Path Routing: Specifies whether calls exceeding link capacity can fail over to the public Internet or be routed across alternative secondary WAN circuits.
• Location-Based Routing Boundaries: Confirms the administrative trust relationship between regional boundaries when evaluating PSTN toll bypass prevention rules.

Before configuring an inter-region link, both participating parent regions (e.g., UK-Region and EMEA-Region) must already exist within the tenant configuration via New-CsTenantNetworkRegion.

Connecting to the Microsoft Teams PowerShell Module

To administer tenant network topologies, launch an elevated PowerShell console and authenticate to Microsoft 365 using the Microsoft Teams module:

# Install the module if not already available
Install-Module -Name MicrosoftTeams -Scope CurrentUser -Repository PSGallery -Force

# Authenticate with administrative credentials
Connect-MicrosoftTeams

Confirm that your user account holds the Teams Administrator role in Microsoft Entra ID before running network topology cmdlets.

Auditing Existing Network Regions and Inter-Region Links

Review the configured regions to ensure you have the exact NetworkRegionID strings for the endpoints you intend to connect:

# Retrieve all existing network regions
Get-CsTenantNetworkRegion | Select-Object NetworkRegionID, CentralSite, Description

# Audit existing inter-region links
Get-CsTenantNetworkInterRegionLink | Select-Object InterNetworkRegionLinkID, NetworkRegionID1, NetworkRegionID2, BWPolicyProfileID

Creating a New Tenant Network Inter-Region Link

To establish a logical WAN interconnect between two existing regions, execute the New-CsTenantNetworkInterRegionLink cmdlet, specifying the two region identifiers and a unique link name:

# Create a direct link between UK and EMEA network regions
New-CsTenantNetworkInterRegionLink -InterNetworkRegionLinkID "UK-to-EMEA-WAN" `
    -NetworkRegionID1 "UK-Region" `
    -NetworkRegionID2 "EMEA-Region"

# Create a trans-Atlantic link between UK and North America regions
New-CsTenantNetworkInterRegionLink -InterNetworkRegionLinkID "UK-to-NA-WAN" `
    -NetworkRegionID1 "UK-Region" `
    -NetworkRegionID2 "NA-Region"

The order of -NetworkRegionID1 and -NetworkRegionID2 does not affect traffic direction; the link represents a bidirectional WAN channel between the two regional hubs.

Associating Bandwidth Policies to the Inter-Region Link

By default, an inter-region link allows unconstrained bandwidth consumption. To enforce Call Admission Control limits, create a bandwidth policy profile and bind it to the inter-region link using Set-CsTenantNetworkInterRegionLink:

# Bind an existing bandwidth policy profile to the UK-to-EMEA link
Set-CsTenantNetworkInterRegionLink -InterNetworkRegionLinkID "UK-to-EMEA-WAN" `
    -BWPolicyProfileID "HighCapacity-WAN-Policy"

# Verify the link configuration with associated bandwidth profile
Get-CsTenantNetworkInterRegionLink -InterNetworkRegionLinkID "UK-to-EMEA-WAN" | Format-List

Associating a BWPolicyProfileID instructs Teams to monitor active real-time RTP/RTCP session metrics across the link, preventing over-subscription when concurrent calling spikes occur.

Removing a Tenant Network Inter-Region Link

If corporate WAN architecture changes, or if regions are consolidated into a unified global hub, dismantle obsolete links using Remove-CsTenantNetworkInterRegionLink:

# Safely remove an obsolete inter-region link
Remove-CsTenantNetworkInterRegionLink -InterNetworkRegionLinkID "UK-to-NA-WAN"

# Confirm removal from the tenant topology
Get-CsTenantNetworkInterRegionLink

Validating End-to-End Enterprise Voice Network Topologies

After defining network regions, sites, subnets, and inter-region links, perform an aggregated diagnostic check to confirm topology integrity:

# Summarize all inter-region links and endpoints
Get-CsTenantNetworkInterRegionLink | Select-Object InterNetworkRegionLinkID, NetworkRegionID1, NetworkRegionID2, BWPolicyProfileID | Format-Table -AutoSize

# Audit all child sites linked to regions participating in WAN links
Get-CsTenantNetworkSite | Select-Object NetworkSiteID, NetworkRegionID, Description

Ensuring that all WAN links are correctly defined and mapped to legitimate parent regions prevents routing errors, optimizes media path quality, and guarantees consistent Call Admission Control enforcement across enterprise Microsoft Teams environments.