By default, when an end user’s corporate account being assigned with a Microsoft Teams product license*, he/she can place video and/or audio call within Microsoft Teams client. But in order to enable your end user to dial the regular telephone phone numbers (E.164 format) or mobile phone numbers you must use Microsoft Phone System to connect to the Public Switched Telephone Network (PSTN).
Generally speaking, there five of options that you can choose when you planning to implement PSTN with Microsoft Teams:
- Microsoft Phone System (Teams Phone) + Calling Plan
- Microsoft Phone System (Teams Phone) + Direct Routing
- Microsoft Phone System (Teams Phone) + Operator Connect
- Microsoft 365 Business Voice + Calling Plan (Business Voice planned to deprecate on March 1, 2022)
- Microsoft 365 Business Voice + Direct Routing (Business Voice planned to deprecate on March 1, 2022)
Let’s dive in each of these options to find suitable scenarios. (Due to Microsoft 365 Business Voice is planning to deprecated on March 1 2022, we’ll only focus on three of main options)
Microsoft Phone System (Teams Phone) + Calling Plan
As writing this article the Microsoft 365 Business Voice + Phone System (Teams Phone) is the most simplest solution to implement and ideally is intend for small to medium business organization with less than 300 end users. And it bundles Private Branch Exchange (PBX) features, a Domestic Calling Plan, Audio Conferencing, Caller ID, Voice Mail, Call Menus, etc.
If your organization purchased one of the following subscriptions, then you can just purchase Microsoft 365 Business Voice add-on license with Calling Plan (either Domestic Calling Plan and International Calling Plan or both) to leverage Microsoft cloud-based telephony solution and PSTN connectivity to enable the end users dial or receive external phone calls.
Microsoft 365 Business Basic
Microsoft 365 Business Standard
Microsoft 365 Business Premium
Microsoft 365 F1
Microsoft 365 F3
Office 365 F3
Microsoft and Office 365 Enterprise E1 or E3
Microsoft 365 and Office 365 Education A1 or A3
Microsoft 365 and Office 365 Government G1 or G3
Microsoft 365 Nonprofit Business Basic
Microsoft 365 Nonprofit Business Standard
Microsoft 365 and Office 365 Nonprofit E1 or E3
As forementioned, after March 1, 2022, the Microsoft 365 Business Voice add-on license will no longer available. You will have to purchase Microsoft Teams Phone with Calling Plan bundle for small to medium business organization with less than 300 end users and if the Calling Plan is available in your country or region.
One thing here to remember is that even though Teams Phone with Calling Plan bundle is similar to Microsoft 365 Business Voice + Calling Plan, but it does not include Audio Conferencing feature. Audio Conferencing feature is now included into Microsoft 365 bundles.
Microsoft Phone System (Teams Phone) + Direct Routing
If Calling Plan is not available in your country or region, and your organization need to retain your current phone numbers with PSTN carrier, you can choose to connect to one or more certified SBCs (Session Border Controller) with Teams Phone license.
With this option your end user’s business phone number without being changed, and you can switching to another telephony carrier if you preferred.
But do pay a attention to this option as you’ll have to maintaining a small piece of hardware (the Session Border Controller) and having decent Internet connection to Microsoft 365 services.
Microsoft Phone System (Teams Phone) + Operator Connect
The Microsoft Phone System (Teams Phone) with Operator Connect option is similar to Microsoft Phone System (Teams Phone) with Direct Routing to provide PSTN connectivity with Teams and Phone System. Except you do not have to concern and maintain the infrastructure as long as your preferred carrier is participant in Microsoft Operator Connect Program.
With this option, your carrier will manage the PSTN calling services and SBCs (Session Border Controller) for your organization, and you can saving the cost with burden.
Some notes here:
*1
Teams Phone is a license not a physical device for Microsoft Teams, it was previously named Microsoft Phone System. And for end user it also changed to “Microsoft Teams Phone Standard” license.
*2
Only within Microsoft 365 E5 plan that you can separately enable/disable Microsoft Teams product license.
