Microsoft Teams Voice: Select the Best Calling Option for Your Business

Businesses that want to enable external voice calling through Microsoft Teams can choose from a Microsoft Calling Plan, Direct Routing, or Operator Connect. This blog outlines key questions to help you select the best option for your needs.

August 18, 2021

While Microsoft Teams (Teams) is a well-rounded productivity tool with millions of daily active users, the core capabilities don’t include the ability to make calls via the Public Switched Telephone Network (PSTN.)

There are a number of ways to add voice calling capabilities to Teams, however it’s important to ensure the solution you choose meets your employees’ and customers’ needs. Keep reading to learn about Teams calling options, and determine which PSTN calling integration is best for your business.

Why Should You Use Microsoft Teams for Calling?

Teams supports the ability to make VoIP calls from user to user. Microsoft offers three options that enable users to make, receive, and transfer calls in Teams via the PSTN:

  1. Microsoft Calling Plan: Essential calling features provided by Microsoft to handle basic calling needs. Easy to add on but may not provide enough coverage.
  2. Direct Routing: Comprehensive calling features provided by a third-party voice specialist to provide more benefits and international coverage. Requires customized integration.
  3. Operator Connect: Calling provided by a select group of specialists pre-approved by Microsoft. Comes with all of the Direct Routing benefits and more and is easy to add on.

By adding voice to Teams, your business gets a single point of access for communications that’s accessible through any device. Teams is evolving into a powerful PBX system for businesses. When you leverage its calling options, you can create a seamless interface while also saving money, time, and maintenance that would be needed to upkeep traditional telecom.

Learn More About Microsoft Teams Voice

Business VoIP Options: Microsoft Calling Plans, Direct Routing, and Operator Connect

Below are key features and considerations when choosing among a Microsoft Calling Plan, Direct Routing, and Operator Connect. Before selecting an option, it is important to understand your company's core communication needs.

Specifically, be sure to evaluate:

  1. The size, complexity, and geographic spread of your company.
  2. Regulatory requirements within your industry that will influence the functionality and compliance you’ll need.
  3. Existing hardware that you need to protect and manage or dismantle and discard.
  4. The level of expertise and available resources in your IT department to implement and manage an added calling service to Teams.
  5. How you will maintain the relationship with your existing PSTN carrier.

Take stock of these factors and read on to see which solution will be the best fit.

choose, voice, calling
Businesses can choose how to enable voice calling.



Microsoft Calling Plan

Direct Routing

Operator Connect

Voice Connectivity

Provided by Microsoft

External carrier services are connected to Teams via a cloud-based or on-premises session border controller (SBC)

Provided by one of the Microsoft-approved Operator Connect providers through trusted cross connects between their network and Microsoft

Voice Service Management

Managed in the Microsoft 365 admin center

Number and services are managed through the carrier’s customer portal

Managed through the Microsoft 365 admin center and the carrier’s portal


Only supports applications designed for Teams using 365 API integrations

Voice application integrations are fully supported by most carriers

Only supports applications designed for Teams using 365 API integrations


Bundled calling plans, minutes, and licensing on a per-user, per-month basis

Pay-as-you-go model, pay carriers for minutes used plus licensing fees

Pay-as-you-go model, pay carriers for minutes used plus licensing fees

Global Coverage

Limited to the approx. 26 countries where Microsoft offers service

Worldwide coverage in countries where third-party carriers can provide PSTN replacement services

Worldwide coverage in countries where approved Operator Connect carriers can provide PSTN replacement services 


Option 1: Microsoft Calling Plans

Key Features

A Microsoft Calling Plan is an add-on telephone plan that becomes the voice solution for your business when combined with Microsoft Phone System. Microsoft offers calling plans on a per-user basis, available domestically and internationally. Adding Calling Plan turns Teams into a hosted PBX solution with service provided directly from Microsoft via Office 365 instead of a third-party carrier.

Key Considerations

Before choosing to take the route of a Microsoft Calling Plan, it’s important to note a few key considerations. First and foremost, plans can be quite expensive, and these plans are only available in select countries. If reliable international calls are of great importance to your business, Microsoft Calling Plan may not be the best fit. Further, if you already have a contract with a PSTN carrier or you need additional licenses for toll-free numbers, you might consider a different calling option.

Here are a few of the primary considerations if you’re thinking about adopting a Microsoft Calling Plan:

  • Office locations: Because Calling Plans aren’t available everywhere, check to see if you have offices in areas that aren’t included in the coverage area.
  • Use of existing PBX infrastructure: If you want to keep using on-prem resources, you may want to find a calling plan or carrier that allows you to use existing infrastructure in addition to a hosted solution.
  • Functional and support needs: Understanding your business’s communication and support requirements will help you determine if a Microsoft Calling Plan is right for you. With this option, you have access to Microsoft support teams that have deep knowledge of Microsoft products and platforms. This close collaboration with Microsoft eases the burden of interviewing and managing providers. 


Option 2: Direct Routing

Key Features

If you’re looking to add voice calling to Teams but want to do so under the direction of voice experts, Direct Routing is a suitable option. Direct Routing gives you greater control and assistance, lower costs, greater flexibility, and wider geographic coverage than Microsoft Calling Plans do.

Key Considerations

This feature is primarily designed for organizations set on using Teams as a PBX but want more flexibility than Microsoft’s preset calling plans. Direct Routing addresses the following: 

  • Degree of Teams adoption: Businesses already using Teams for internal communications can leverage the platform for their external communications too. Direct Routing eliminates the need for your IT team and users to learn a new system. 
  • Availability of in-house expertise: Any business with a smaller IT team (or none at all) can get expert support when using Teams as a PBX. With a bring-your-own-carrier model, an experienced provider (like Intrado) gives you step-by-step account management and can install Direct Routing for you.
  • Desired flexibility: Direct Routing enables greater flexibility and autonomy, and it allows for negotiation. If you have complex calling requirements and want to have more control over your company’s telecom resources, Direct Routing affords that autonomy with room for customization. 


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A strong telephony partner makes all the difference.


Option 3: Operator Connect

Key Features

Operator Connect is known as the next iteration of Direct Routing. It delivers all of the key features of Direct Routing, but it is even easier to add calling. It’s a partner offering that allows users to bring their own carrier, or “operator,” to Teams. The carrier then plugs PSTN calling into Teams. In addition to the features listed with Direct Routing above, Operator Connect offers direct peering, simplified management, and a shared service-level agreement. It also has dedicated conferencing support through Operator Connect Conferencing.

Key Considerations

Like its features, the considerations to keep in mind when evaluating Operator Connect are also similar to Direct Routing. But because Operator Connect is easier for users to set up—just a few clicks in the admin center—the primary considerations are related to the carrier you select and the calling requirements of your business.

  • Carrier of choice: Users can select from a list of approved operators, Intrado included, that will provide PSTN connection. These carriers have been vetted by Microsoft and offer technical telecom and Teams service and support. If your existing carrier is an approved Microsoft Operator Connect carrier, the choice and system deployment will be even easier. 
  • Resource and infrastructure management: If you want to remove the burden of bringing your own calling solution to Teams, Operator Connect is your answer. The qualified carrier you select will handle all technicalities and infrastructure management, including overseeing PSTN connection and the SBC. 


voice, calling, business, communications, Teams
Unlock the potential of business communications with voice calling through MS Teams.


Intrado Is Here to Support Your Calling Needs

For businesses that want to move forward with Direct Routing or Operator Connect, Intrado can support the implementation and offer guidance through the process. Intrado is among the select few Gold-Certified Microsoft Direct Routing and Operator Connect Conferencing partners and has deep expertise in helping businesses optimize their use of Teams as a calling solution.

To learn more, download our whitepaper: A Practical Guide to Adding Voice to Microsoft Teams

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