Migrating Voice to Microsoft Teams


Leading Private Equity firm migrates Voice services to Microsoft Teams to boost innovation and workforce mobility with MS Teams calling and agile cloud communications.



One of Europe’s leading private equity firms, Terra Firma creates value for its stakeholders by investing in asset-rich businesses. The firm’s advisory team is made up of more than 50 experts located in London and Guernsey.

Fast, reliable communications are key to success, enabling multidisciplinary teams to efficiently share their unique knowledge. When Terra Firma needed to improve business continuity and voice communications it turned to technology partner DoubleEdge.

This saw rigid on-prem telephony and expensive ISDN lines replaced with Voxivo4Teams, the award-winning Foehn cloud phone and unified communications system.

Calling with MS Teams

“DoubleEdge understands our business. They’re more than just an IT provider – they’re an innovation partner. Over the last 15 years they’ve been excellent at scouting the market and bringing new ideas to the table.”

Lee Colvin – Head of IT and Infrastructure, Terra Firma Capital Partners.

Microsoft Teams phone system integration

Calling With Microsoft Teams

Terra Firma, like many organisations, had quickly embraced Microsoft Teams for collaboration, but had been nervous about migrating their telephony. Voxivo4Teams removed those concerns and DoubleEdge was with Terra Firma every single step of the way.

“Moving to hosted telephony laid the foundations for cloud-based agile working,” added Colvin. “Unlike other SIP providers offering like-for-like solutions, DoubleEdge looked to add flexibility and neat features.”

Going The Extra Mile…

Nothing was left to chance. Using a pre-validated design DoubleEdge specialists built the Voxivo4Teams solution alongside MS Teams taking care to ensure it worked with existing SIP devices.

Right down to the smallest detail like creating DDI dummy lists and testing analogue phone adapters. Regular project meetings kept things on track.

For example, when call recording requirements changed DoubleEdge came up with a cost-effective workaround without adding delays. New requirements, such as connecting up Zoom Rooms door entry systems, fax lines and conference room phones were quickly dealt with too.

“Some providers just want to sell you licences and walk away,” noted Colvin.

“DoubleEdge were the exact opposite and were with us every step – from project scoping and design meetings to interoperability testing and helpful demos. Their attention to detail reduced risk and lead times, enabling us to safely migrate 55 users at our London Office overnight.”

The next day DoubleEdge carried out a rigorous check of number porting and routing to ensure no calls were lost, before formally handing over the system.

The communications upgrade prepared Terra Firma for what was about to hit as COVID-19 started to sweep across Europe.

“Working with DoubleEdge provides fast access to more expertise and solutions from other Kerv Group companies.

They arranged a trial of Voxivo4Teams so we could quickly try it out. That saved so much time in solution evaluation and procurement.”


Lee Colvin, Head of IT and Infrastructure, Terra Firma

Teams Direct Routing benefits

MS Teams Phone System Integration

Voxivo4Teams was set up with Microsoft Teams Direct Routing as part of a hybrid approach. Importantly, it ensures quality Teams call recordings for compliance purposes – a prerequisite for financial services companies.

So, when the pandemic struck, Terra Firma changed to remote working without any problems or the expense of Microsoft Voice call plans.

“We already used Teams as our go-to collaboration platform,” said Colvin.

“Now, you simply click on an icon to receive and make calls through your desktop. We haven’t seen any loss in productivity. Our employees work just as efficiently from home as they do in the office.

They can connect over calls, video and chat – anytime, anywhere – and manage the entire investment process from business acquisition through transformation to exit.”

In addition, Voxivo4Teams has provided a 50% cost saving through cheaper calls, reduced maintenance and retiring the old PBX system, circuits and handsets. “We simply buy per-minute voice bundles so it’s effectively pay-as-you-go,” added Colvin.

Voxivo4Teams Key Features

Intuitive Management Portal

Intuitive Management Portal

Drag & Drop Dial Plan Editor

Drag & Drop Dial Plan Editor

Analytics Dashboard

Analytics Dashboard

Call Recording

Call Recording

Native Teams Integration

Native Teams Integration

Real-Time Cost Estimator

Real-Time Cost Estimator

Teams with enhanced telephony features

By leveraging Voxivo4Teams, Terra Firma has injected serious punch to Microsoft Teams with essential telephony features such as call queuing, hunt groups and auto attendant.

Other benefits include improved reporting and cost analytics, along with better administration tools.

“We’re a relatively small IT team of three, but Voxivo4Teams puts us firmly in control of business communications,” said Colvin. “And it’s so easy to use with intelligent routing and drag-and-drop dial plan editing.”

While staff have been working from home, the IT team has been busy making the London office COVID-safe. “To Voxivo4Teams, Zoom Rooms is just another SIP endpoint,” concluded Colvin.

“That’s enabled us to create more breakout and meeting spaces throughout the building. So, when staff return, they’ll be able to safely collaborate with overseas colleagues, clients and third parties like banks, lawyers and accountants.”


We believe that proactive, knowledgeable support from people who really care is at the heart of delivering performance improvement.


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