Phone system direct routing

You've completed Get started. You've rolled out Teams with chat, teams, channels, & apps across your organization. Maybe you've deployed Meetings & conferencing. Now you're ready to add cloud voice workloads, and you've decided to use your own telephony carrier for Public Switched Telephone Network (PSTN) connectivity by using Phone System Direct Routing. With Direct Routing, you can use Phone System with virtually any telephony carrier.

This article describes core deployment decisions for Direct Routing as well as additional considerations you may want to think about, based on your organization's needs. You should also read Cloud Voice in Microsoft Teams for more information about Microsoft's cloud voice offerings.

Learn more about Direct Routing

The following articles provide more information about configuring and using Phone System Direct Routing. Configuring Direct Routing requires understanding of PSTN routing design. You should read all of these articles to understand how to plan and configure Direct Routing:

In addition, you might want to read the following articles depending on your requirements:

Core deployment decisions

These are the core decisions to consider for Direct Routing.

Ask yourself Action
For which users will I enable Direct Routing? For more information, see Enable users for Direct Routing Service.
Do I have the required licenses for Direct Routing? For more information, see Licensing and other requirements.

Session Border Controller (SBC) considerations

With Direct Routing, you connect your own Session Border Controller (SBC) directly to Phone System. For a list of certified SBCs, see Supported Session Border Controllers.

Ask yourself Action
Where and how will I deploy SBCs? For more information, see Configure Direct Routing
Do I have multiple tenants? For more information, see Configure a Session Border Controller for multiple tenants.

Voice routing considerations

You'll need to configure Phone System to route the calls to the specific SBCs.

Ask yourself Action
What voice routing policies, PSTN usage, and voice routes do I need to create? For voice routing information, see Configure Voice Routing.
Which users will be assigned to the voice routing policy that I define? See the examples in Configure Voice Routing.

Ensure incoming calls land in the Teams client using TeamsUpgradePolicy

Direct Routing is only supported with Microsoft Teams. To receive PSTN calls through Direct Routing, you need to configure TeamsUpgradePolicy to ensure incoming calls are received in Teams. Users must be in Teams Only mode, which you can do by assigning them the "UpgradeToTeams" instance of TeamsUpgradePolicy.

Ask yourself Action
What does Teams Only mode mean? For more information, see Migration and interoperability guidance for organizations using Teams together with Skype for Business.

Additional deployment considerations

You may want to consider the following, based on your organization's needs and configuration:

Ask yourself Action
Do you have an existing Skype for Business Server deployment with hybrid connectivity configured? To understand how user accounts in a hybrid environment are provisioned and managed, see User accounts in a hybrid environment with PSTN connectivity.
Are you migrating to Direct Routing from Calling Plan or from a Skype for Business on-premises environment? To understand more about migrating to Direct Routing from an existing environment, see Migrating to Direct Routing.