To connect Teams Phone to the PSTN, you can choose from the following options:
- Calling Plan—a native cloud-based solution in which Microsoft acts as your PSTN carrier
- Operator Connect—a PSTN solution for organizations whose existing carrier is a participant in the Microsoft Operator Connect program
- Direct Routing—a service that enables you to use any PSTN carrier by connecting your Session Border Controller(s) (SBC) to Microsoft Phone System
Calling Plan is the Teams solution for anyone who wants to get PSTN connectivity without having to install or maintain any additional equipment. Because it is cloud-based, only an internet connection with sufficient bandwidth is needed to connect via Calling Plan.
The Calling Plan option is available with different plans and prices to suit the requirements of different users. For example, you can configure your Teams Licenses so that only certain users have access to Calling Plan.
If your Microsoft package includes Teams with Calling Plan, 8x8 Voice can be synced with Teams so that users don’t have to navigate different interfaces.
If your current operator is a participant in the Microsoft Operator Connect Program, they can manage the SIP trunking process and help you connect Teams to the PSTN.
For a list of operators participating in the Microsoft Operator Connect Program see the Microsoft 365 Operator Connect directory.
Direct Routing is Microsoft’s solution for users who wish to use Microsoft Phone System to integrate Teams with the rest of their physical and digital telephony infrastructure. For example, integrating Teams with your on-premises or cloud-hosted private branch exchange (PBX) would require direct routing.
Direct routing lets you connect a supported Session Border Controller (SBC) to Microsoft Phone System. A SBC is the device that controls how a private network interacts with the broader telephone system. If you want to configure on-premises PSTN connectivity with the Microsoft Teams client, you would use a SBC to do so.
Direct routing with 8x8
8x8 Voice for Microsoft Teams is a cloud-based PBX-to-PBX integration for the Microsoft Phone System, which allows 8x8’s phone service to be seamlessly integrated with the Microsoft Teams environment.
8x8 Voice provides enterprise-grade telephony and global PSTN connectivity to customers who want to retain Microsoft Teams as their primary collaboration interface.