How to integrate any call control, UC or PBX into Microsoft Teams

Here's what you probably already know - Microsoft Teams is the most popular option out there for collaboration. Catering to both business and education, its rise from 44M monthly active users in 2020 to over 320M today was nothing short of miraculous. The platform continues to provide each of those users with a real-time collaborative tool for chat, video, file sharing and app sharing and the Microsoft currently holds a 46% share of the UC&C market.

Despite the impacts that it is having worldwide, what is less well known is that Microsoft Teams is also a powerful tool for enabling external communications. On this point, enterprises & SMBs alike are realizing the ever-increasing list of benefits for using Microsoft Teams Phone as a voice solution and are approaching their voice and IT Providers for answers.

Analysts are confident that the number of PSTN enabled Teams users will grow to 50 million in the next few years, and with the bulk of those going through Microsoft calling partners, there is plenty of opportunity for providers to use the rise of Microsoft Teams Phone to their advantage - With Teams Phone you can not only evolve your existing proposition but also unlock brand new sets of customers and incorporate new IT targets that were previously unreachable.

But it's tricky to know how to unlock this opportunity without the required knowledge and internal expertise. And that's why we're here - to help you build a solution that grows alongside on the success of Microsoft Teams and plugs directly into your customers' existing phone systems. There are a few ways to do this, including Microsoft Operator Connect, but today we're going to be focusing on the one method that is purposely designed to have a minimal impact on existing setups.

Is it possible to integrate an existing telephone system with Microsoft Teams?

There's a pretty straightforward answer here - Yes, you can integrate a wide range of existing telephone systems into Microsoft Teams with a method called Direct Routing. Direct Routing enables users to make and receive phone calls to and from landlines and mobiles via the public switched telephone network (PSTN) using Teams.

Not only is Direct Routing compatible with virtually all phone systems (including both cloud-based and on premise setups), it's also not specific to any specific call control, PBX or UC and you can even deploy a Direct Routing as a Service (DRaaS) option with minimal investment, resource and risk. By offering a Direct Routing as a Service (DRaaS) option you can even provide a rolling contract with no need to install any extra on-premise equipment of software. 

What are the advantages of Direct Routing?

For businesses, there are a number of advantages that come with using Direct Routing to enable voice. Not only does it allow organizations to optimize their existing setup whilst making the most of collaborative working in Microsoft Teams, it also means that:

• Existing numbers can be ported, meaning there is no disruption to existing setups
• High levels of flexibility can be incorporated so that ease of use is maximised
• It enables huge amounts of cost savings and allows retention of existing infrastructure which in turn gives on-prem focused businesses the breathing room they need to execute a cloud migration

Direct Routing presents an opportunity for Providers to grow relationships, to grow revenue, and to increase deal sizes, and here's how:

• It's an efficient way to address the growing market of PSTN enabled Teams users
• It allows you to target Microsoft-forward organizations
• It keeps you ahead of the curve in terms of cloud-based voice whilst acting as the perfect enabler for on-premises systems
• It helps to futureproof your offering by tapping into the world's most popular collaboration platform

What is the easiest way to set up Direct Routing?

Direct Routing is just the name for the bundle of tech that make a connection between Microsoft Teams and an existing phone system possible, so it is technically doable for you to build it yourself. With this being said, creating a Direct Routing solution from scratch takes massive amounts of expertise, time and resource and there are a good many pitfalls that can occur during setup, not to mention that to have a successful Direct Routing solution you have to also develop your relationship with Microsoft themselves (so here is the hard sell, I'll keep it quick).

The best way of avoiding these pitfalls and to ultimately get the best results in the fraction of the time, with a fraction of the effort and investment is to deploy a Direct Routing as a Service (DRaaS) solution with the help of Call2Teams, which bridges the gap between Teams users and virtually any UC, PBX or SIP Trunk.

If you're looking to learn more about exactly how you can leverage Direct Routing and the success of Microsoft Teams, why not get in touch today.

Last updated: 07/01/25