When the existing phone system only works with custom solutions, onboarding new employees is a hassle, or Microsoft Teams runs alongside landline phone service, communication becomes unnecessarily complicated. A PBX Migration It doesn't just create a new technical foundation here. It determines whether your company will remain reachable at the same phone number in the future, whether employees can work flexibly, and whether calls are reliably routed to the right people.
The transition from a traditional system to a cloud PBX or a modern on-premises IP phone system is not merely a hardware replacement. Phone numbers, end devices, internet connections, security requirements, Teams integration, and existing business processes must all be compatible. Clarifying these dependencies early on reduces risks and prevents having to make the switch under time pressure.
Why a PBX Migration Is More Than Just a System Upgrade
Many companies initiate a migration because vendor support is ending, ISDN lines need to be replaced, or maintaining the old system is becoming disproportionately expensive. While this is understandable, it doesn’t tell the whole story. The real benefit comes when the new solution simplifies day-to-day collaboration.
A modern PBX combines landline telephony, mobility, and collaboration in a manageable environment. Employees can use their desk phones, in the softphone or make calls directly in Microsoft Teams. Call reception groups, scheduling, IVR menus, and call forwarding can be managed centrally. New locations or work-from-home setups do not necessarily require their own on-site phone system.
Whether a cloud PBX or an on-premises installation is a better fit depends on your requirements. A cloud solution reduces operational overhead and scales well. An on-premises PBX may be a good choice if specific integrations, regulatory requirements, or existing infrastructure make it the right option. The key factor is not the operating model alone, but rather a clear architecture that ensures availability, security, and ease of administration.
Accurately Assess the Current Situation Before the PBX Migration
A thorough assessment prevents what may seem like minor issues from becoming roadblocks as the project progresses. This is not just about the number of extensions. Other relevant factors include the phone number structure, call volume, locations, end devices, and applications that rely on telephony.
In particular, check which main numbers, extension blocks, and service numbers are in use. For customers and suppliers, the familiar number is often more important than the technology behind it. Number porting must therefore be prepared correctly in terms of timing, organization, and contracts. Incorrect owner information, incomplete powers of attorney, or simultaneously initiated cancellations can jeopardize the porting date.
Equally important are devices that aren’t immediately obvious: door intercoms, alarm systems, postage meters, elevators, fax solutions, or machines with analog interfaces. Not every device can be operated effectively via VoIP. In some cases, an adapter is needed; in others, a cellular or specialized solution is required. Anyone who discovers these issues only on the day of the switchover risks outages in security-critical or business-critical areas.
The network side also needs to be put to the test. Voice quality depends on more than just the nominal bandwidth. Prioritization via Quality of Service, sufficiently sized Internet connections, stable Wi-Fi coverage, and Separate voice VLANs directly affect call quality. If there are multiple locations, it should be clear how redundancy, VPN connectivity, and an Internet outage will be handled.
Define the Target Vision: Accessibility First, Features Second
Even the best phone system is useless if calls go unanswered during vacations, sick leave, or peak periods. So don’t start by asking about individual features—start with the most important call routes: How does a new customer reach the sales team? Where does a call go outside of business hours? Who picks up the call if the line is busy or after a set number of rings?
These processes form the basis of the dial plan. It maps out main numbers, queues, groups, overflow routes, voicemail, and time profiles. In smaller companies, this can intentionally remain simple. Organizations with multiple departments, languages, or locations usually require clearly defined routing rules and responsibilities for maintaining them.
Microsoft Teams This requires a decision of its own. Should Teams be used only for internal meetings, or should it serve as a full-fledged telephony workstation? In the latter case, external dial-in, phone number assignment, presence information, call forwarding, and emergency call locations must be reliably configured. Native integration prevents additional media breaks and makes the system easier for employees to use. However, it does not replace the need to plan roles, permissions, and call workflows.
Plan for Security and Availability from the Start
IP telephony is part of your IT infrastructure and requires the same level of protection as other business-critical systems. Open SIP ports, weak passwords, or uncontrolled international dialing destinations can lead to misuse and unexpected costs. A Session Border Controller protects the interfaces between your internal network and your telephony provider, manages SIP connections, and supports secure site connectivity.
Clear authorization policies, secure administrative access, and logging are also recommended. For companies operating internationally, calling permissions can be restricted based on role or cost center. For example, the reception desk can make both domestic and international calls, while other extensions are only granted access to the destination areas they actually need.
Availability must be planned in concrete terms. What happens in the event of an internet outage, a power outage, or a disruption at the main location? Mobile fallback locations, automatic call forwarding, and redundant connections can ensure reachability. The appropriate measure depends on the business criticality. A medical center, a customer service department, or an emergency hotline requires a different approach than an office that receives only a few incoming calls.
Here's how the transition will take place in a controlled manner
A successful migration is carried out in clear stages. First, the new environment is set up and tested with selected employees. This is followed by end devices, groups, and integrations. The porting of phone numbers is not scheduled until the processes have been tested in practice and all parties involved are familiar with the migration plan.
For the actual transition, there should be a brief, definitive timeline:
- Identify points of contact and escalation procedures for the switchover day.
- Test call forwarding, call queues, emergency call configurations, and important destinations.
- Pre-register and label end devices, softphones, and Teams workstations.
- Define a fallback plan for critical phone numbers and temporary availability.
Operating in parallel can be useful in complex environments, but it isn’t always necessary. It increases security but also incurs additional costs and administrative work. For a manageable installation with a thoroughly tested cloud PBX, a scheduled switchover outside of business hours is often sufficient. For multiple locations or extensive CTI integrations, a phased approach is usually the better choice.
Employees Decide on Acceptance
Technically, a new telephony solution can be perfectly configured and still fail if employees are unfamiliar with its basic functions. Habits are changing, especially with Teams telephony: presence status, call forwarding, call delegation, and switching devices must be explained clearly.
Short, role-specific orientations are more effective than general training for everyone. The reception desk needs guidance on managing lines and covering for absent staff. Managers often need to delegate tasks. Mobile employees must know how to remain professionally reachable via their business number while on the go. Supplement the orientation with a simple internal guide and a designated point of contact for the first few weeks.
Even after the go-live, it’s worth taking a look at analytics and feedback. Are calls being disconnected too often? Are there call queues at certain times? Are call forwarding settings still up to date? A PBX should evolve with the company, rather than remaining unchanged for years after implementation.
Compare Costs Realistically
When calculating the cost-effectiveness, it’s not just monthly license fees that matter. You should also factor in internet connectivity, end devices, project costs, porting, security components, support, and internal administrative overhead. An inexpensive standalone solution can end up being costly if you have to coordinate multiple providers for team calling, SBCs, firewalls, or site-to-site networking.
Conversely, not every feature is necessary for every company. Companies with few workstations and simple reachability rules do not need a complex contact center configuration. Predictable flat-rate plans are suitable for high call volumes, while per-minute billing may be more cost-effective for low or highly fluctuating demand.
An experienced partner like Winet can design a comprehensive solution that integrates telephony, number porting, Teams integration, networking, and security components. This streamlines the coordination process, but it does not replace the need to jointly clarify your internal processes and responsibilities.
The best way to prepare for your migration is to conduct a realistic test: Simulate a typical customer call from the first ring all the way to the appropriate person—during business hours, after hours, and in the event of a workstation outage. If this process works reliably, your new phone system will not only be modern but will also truly be better in everyday use.
Current
How does Swiss number portability work?
Guide to Microsoft Teams Calling
Cloud Telephony for Teams That Are Always Reachable
Teams, phone service, or VoIP—which one is right for you?
IP Phones in the Office for Modern Businesses
