Teams Phone PSTN Connectivity Options


With Microsoft Teams Phone, you always need to choose a PSTN connectivity option for your users. PSTN connectivity and phone numbers are not included in any license suite. It requires either an add-on license from Microsoft or service from another provider, such as Pure IP.

This article takes you through the options to help you decide the best option for your users.

These options are set on a per user basis, you can mix and match the different options to meet your needs globally. Having a combination of options is the most common approach.

Microsoft Calling Plans


Available directly from Microsoft, all served from the cloud. These are bought on a per user basic and include a user DDI and a minutes allowance. The common plans are:

  • Domestic
  • Domestic and International
  • Pay As You Go

The allowances stack if they are the same plan type and same country. Meaning if you buy two France domestic plans for 2 users, each plan comes with 1200 domestic minutes, so the users have a combined 2400 minutes to use before they cannot make a call or move to paying per minute for the excess usage. If I buy a UK user domestic plan, this does not bundle up with the France Domestic user plans.

Domestic and international, as the name suggests, includes allowances for both domestic and international calling, whereas on a domestic plan all international calls would be pay per minute.

Microsoft Pay as you go plans still include a cost per user per month, effectively for the DDI, but do not include any minutes and all calls are paid per minute.

Microsoft Calling Plans are quick and easy to get started with but are usually not the most commercially competitive.

Operator Connect


This is Microsoft’s certified option for licensed telecoms providers to offer phone numbers and connectivity in the cloud and is fast becoming the ‘go-to’ option. Providers go through a rigorous onboarding process, both legal and technical, and directly network peer-to-peer with Microsoft.

These providers can then issue phone numbers directly into the Teams Admin Center and provide cloud PSTN services. There are over 70 certified operators to choose from. Pure IP was one of the first operators to certify and has some of the top country coverage globally.

Direct Routing


Today the most common form of deployed PSTN connectivity for Teams. Direct Routing certifies specific Sesson Border Controllers (SBC) models to connect to Microsoft, which then allows you to connect any telephony provider to Microsoft Teams.

There is no certification to become a “Direct Routing Service Provider” so anyone can offer Direct Routing. It is very important to choose a reputable provider. As a customer you can either have your own dedicated SBCs, sometimes required for complex PBX interoperability or regulatory reasons where there is a need to connect to a local provider, such as in India, or many service providers offer “Direct Routing as a service”, where they manage the SBCs in the cloud for you.

Pure IP offers Direct Routing, both with a per customer manager SBC or Direct Routing as a Service. Direct Routing can be used for countries where there is not Operator Connect coverage, many customers mix Direct Routing and Operator Connect to get the right coverage for them globally.

Teams Phone Mobile


The newest connectivity option for Microsoft Teams, a select number of mobile/cell providers can issue business mobile phones where the single mobile number is also the Teams Phone number. Single number, single voicemail, presence reflecting in a call and even compliance call recording of mobile calls if you set it up for Teams.

Teams Phone Mobile is only available from select mobile operators in select countries now, it will likely expand over time. Typically, mobile providers charge an extra fee on top of their business packages for this service.

Another option to give mobile extensibility is to use the Teams mobile app or to use services like Tango Extend to bridge an Operator Connect or Direct Routing number to an eSIM to allow mobile calls to be made with the Teams fixed line number.

How do you choose the right Teams PSTN connectivity for your organization?


There is no one size fits all option for PSTN connectivity, that is why Microsoft provides 4 options. The options can be mixed and matched to give the coverage and service you need. An individual user can only have 1 number of one type, but you could potentially have Microsoft Calling Plans, Operator Connect, Direct Routing and Teams Phone Mobile in a single organization, or technically even in a single country.

From a cost and practicality point of view organisations usually look to rationalize their carriers, so it can be good to look for an operator that can both do Operator Connect and Direct Routing, this combination means they can cover all scenarios.

Other factors to consider include:

  • Cloud country coverage – how many countries can be covered truly from the cloud
  • Commercials, how does the total cost compare
  • Service and Support
  • What other services can the provider offer? SBC management, deployment services, support, moves adds and changes, compliance recording, contact center, integration of other legacy platforms/services?
  • References and market reputation

With over 14 years working with Microsoft customers, we are very confident of our options, service and pricing for any Microsoft Teams organization. We would be happy to have a conversation about the options and see if we can be a fit as your global telephony provider for Microsoft Teams.