Setting Up Audio Conferencing in GCC High and DoD Environments 

Government organizations operating in Microsoft’s Government Community Cloud High (GCC High) and Department of Defense (DoD) environments face unique requirements when enabling collaboration tools like Microsoft Teams.  

While Teams is the standard for secure collaboration across agencies and defense contractors, one limitation in these environments is the lack of native cloud-based Public Switched Telephone Network (PSTN) services. 

In the commercial Microsoft 365 cloud, organizations can enable Teams Audio Conferencing with Microsoft’s own cloud PSTN service. However, in GCC High and DoD, Microsoft does not provide direct cloud PSTN or dial-in conferencing services. That means agencies and contractors need an alternative method to enable dial-in functionality for Teams meetings. The solution is Direct Routing. 

What Is Direct Routing? 

Direct Routing allows organizations to connect Teams to the PSTN through a certified Session Border Controller (SBC) and telephony provider. This setup enables users to schedule and join Teams meetings with dial-in numbers, which is an essential capability for government organizations with strict compliance requirements and diverse user needs. 

At its core, Direct Routing requires three components: 

1. PSTN Trunk: Purchased from a telephony carrier (such as AT&T or Verizon), the trunk connects your organization’s phone service to the wider PSTN, enabling inbound and outbound dialing. 

2. Direct Routing Solution (SBC): An SBC acts as the secure “gateway” between Teams and the telephony service. For GCC High and DoD, Microsoft requires the use of certified SBCs. Microsoft maintains a list of certified SBC and Direct Routing providers, ensuring the solution meets performance and security standards. 

3. Teams Configuration & Licensing: Within the GCC High or DoD tenant, Teams must be configured to connect through the SBC. In addition, each user who needs to schedule meetings with dial-in access requires a GCC High Audio-Conferencing User license. While Microsoft does not charge for these licenses, they must still be assigned for the feature to function. 

How To Enable Audio Conferencing in GCC High and DoD 

Here’s how you can get started with setting up Direct Routing: 

Step 1: Select a Telephony Provider 
Choose a carrier that offers PSTN services for government environments. Look for providers with experience in GCC High and DoD requirements. 

Step 2: Procure a Certified Session Border Controller (SBC) 
Select an SBC vendor from Microsoft’s certified list. The SBC acts as the secure gateway between Teams and your telephony trunk. 

Step 3: Deploy and Configure the SBC 
Install the SBC either on-premises or in a hosted environment. Configure routing rules so Teams can send and receive audio calls through the PSTN. 

Step 4: Configure Teams Direct Routing 
In the Teams Admin Center, configure voice routing policies, PSTN usages, and dial plans to ensure users can connect seamlessly. 

Step 5: Assign Audio Conferencing Licenses 
First, activate the Audio Conferencing Tenant license for your organization. Then, assign Audio Conferencing GCC High (Per User) licenses to individuals who need to host dial-in meetings. There’s no additional cost, but both the tenant and user licenses must be explicitly enabled for audio conferencing to work. 

Step 6: Test and Validate 
Run test calls to ensure dial-in numbers work properly, both inbound and outbound. Confirm compliance and security requirements are met before rolling out broadly. 

Next Steps 

Configuring Audio Conferencing through Direct Routing requires expertise in Teams setup, licensing, and certified telephony integrations. If your organization is ready to enable dial-in conferencing for Teams, reach out to CloudFit for guidance and setup support. 

Sources: 

PSTN Connectivity | Microsoft 

Session Border Controls certified for Direct Routing | Microsoft