Rollercoasters are great for thrill seekers. Not for enterprise voice migrations.
Case in point: Merlin Entertainments, whose voice environment spanned 135 locations across the globe with hotels, resorts, attractions, and offices. The infrastructure mix included analog lines, on-site PBXs, Skype for Business, and thousands of handsets in every shape and standard imaginable.
A shift to Microsoft Teams Phone could have meant long delays, user disruption, or worse - breaking core services like security phones or contact center flows.
But that didn’t happen. Instead, Merlin executed a pragmatic, scalable, and flexible migration with a smart strategy and repeatable steps.
Pure IP supported Merlin throughout this transformation. These are the takeaways that helped keep things steady, even when the landscape wasn’t.
Merlin’s environment was anything but uniform.
Some locations had:
Others had:
Instead of forcing a single template, Merlin built playbooks based on site type, infrastructure maturity, and operational importance. Some migrated in one go. Others followed phased timelines based on risk or staffing.
Takeaway: Migrations fail when you ignore context. Flexibility wins.
Our Teams Phone Migration Guide gives you the essentials: what to know, what to map, and how to avoid downtime across mixed estates.
2. Start early with SIP and stick with what works
Merlin started their project before Operator Connect was launched. They built global SIP trunking into their infrastructure from the start. That decision paid off in speed, consistency, and control.
Rather than juggling local carriers or dealing with telco delays, they partnered with Pure IP as their provider who could deliver global SIP coverage, fast provisioning, and solid porting support.
Takeaway: SIP isn’t just a transport method, it’s a long-term strategy. The earlier you start, the smoother every future migration becomes.
Go behind the scenes with Paul Cornish as he unpacks Merlin’s global Teams Phone migration.
Porting is often the riskiest part of any voice migration. At scale, it’s also the most misunderstood.
Merlin took a measured approach:
At Pure IP, we adopt a unique approach to number porting which we take our enterprise customers, including Merlin, through. We support porting in over 50 countries through a single, coordinated process, backed by dedicated project teams, platform integrations, and automation. Customers get migration trunks to separate porting from go-live, pre-port testing to catch issues early, and zero-touch provisioning into Microsoft Teams. The result is a process that’s predictable, repeatable, and built to scale.
This approach turns number porting from stressor into a strength.
Instead of treating number moves like one-off projects, Merlin integrated porting into the daily rhythm of operations. It became:
Porting success factors:
Takeaway: Build trust in your porting process and scale it like a product.
In an ideal world, you’d start fresh with Teams-certified phones and cloud-native devices. That wasn’t Merlin’s world.
Instead, they supported:
Merlin extended device lifespan and avoided expensive replacements by:
They built an ecosystem that respected the real world — not just the Teams admin center.
Takeaway: You don’t need a perfect estate to move forward. Work with what you have. Choose partners that embrace complexity.
Related: 5 personas you need to plan for in your Teams Phone deployment
Merlin once managed over 25 Ribbon gateways across global data centers. It worked — until it became an operational drag.
As Teams Phone matured, and the SIP trunking strategy solidified, they shifted from in-house SBCs to hosted Direct Routing through Pure IP. The transition gave them:
This wasn’t a rip-and-replace. It was a strategic transfer of responsibility.
Takeaway: The goal isn’t cloud for cloud’s sake — it’s control and scale without the weight of hardware.
Merlin’s journey wasn’t flashy. It was smart.
They didn’t try to reinvent voice. They worked with the mess — the analog lines, the old handsets, the regional quirks — and used smart strategy and solid tech to make it all run through Teams.
They chose tools that adapted to their infrastructure. Partners that delivered. And plans that scaled without chaos.
When the stakes are high and the systems are old, skip the thrill ride. Plan, test, and migrate with confidence.
Yes. Our SIP Connect service bridges analog and SIP registered devices — such as fax machines, entry systems, DECT phones, and video conferencing units — into your cloud telephony environment. SIP Connect creates a secure SIP endpoint per device, unified under our global voice platform. You keep using existing hardware while consolidating management and routing into Microsoft Teams.
Use a hybrid model:
Yes. Use Direct SIP connections from your Teams SBC to cloud contact centers like NICE or Genesys. This allows you to switch numbers between Teams and contact center platforms without re-provisioning.
Pure IP can integrate with most industry-leading contact centers.
Mitigate this by:
Use SIP trunking and Direct Routing to bridge all platforms. You can:
This lets you phase migration without disrupting core services.
It depends on how much control, flexibility, and integration you need.
Use Operator Connect if you want:
Use Direct Routing if you need:
You can also use both — many enterprises do, depending on region, use case, or site complexity.
Not sure which is the better fit? Our Ultimate Guide to Microsoft Teams Calling explains the options, and much more.
Read our guide ➡️ Ultimate Guide to Microsoft Teams Calling