An IP phone in the office is much more than just a replacement for the traditional desk phone. It connects employees at the office, working from home, and on the go using the same business number, the same rules, and professional availability. For companies, this makes telephony a predictable part of their IT infrastructure—rather than an isolated system that requires complicated adjustments whenever changes are made.
Anyone moving into a new office today, replacing an existing system, or making greater use of Microsoft Teams for collaboration should not start by selecting individual devices. The key question is how calls should be handled within the company going forward: across locations, within teams, at mobile workstations, and during outages. This determines the right combination of IP phones, cloud PBX, SIP trunk, internet access, and security strategy.
What an IP Phone Can Do in the Office
An IP phone transmits calls over the data network instead of a traditional telephone line. It connects to the corporate network via Ethernet and, if necessary, is powered directly from the switch via Power over Ethernet. This reduces the amount of cabling required at the workstation, while management and configuration can be handled centrally.
The practical benefits are evident in everyday use: A new employee is assigned a direct extension and can start working right away on a device that’s already set up. A team can move to a different office without having to set up a new phone line. Business hours, call groups, cover arrangements, and announcements can be adjusted in the phone system rather than on each individual phone.
However, an IP phone does not automatically replace the phone system. The end device is just one component. The intelligence lies in the PBX—that is, in the rules governing incoming and outgoing calls, call queues, IVR menus, voicemail, presence status, and access permissions. Especially when dealing with multiple locations or hybrid work arrangements, this level determines the quality of the overall solution.
Which Telephony Architecture Is Right for Your Business
For smaller businesses with few workstations, a hosted cloud PBX is often a good choice. The system is operated in a data center, updates and maintenance can be scheduled, and new users can be added easily. This is particularly appealing when there is no in-house IT team available to operate an on-premises phone system.
Organizations with specific compliance requirements, complex network infrastructure, or existing on-premises systems, on the other hand, may prefer an on-premises PBX. They keep the platform within their own environment and define integrations and security requirements in great detail. However, this increases operational overhead and the responsibility for updates, backups, and redundancy.
Cloud PBX or On-Premises System: It Depends on the Business
The right decision isn't solely a matter of company size. A cloud solution may also be suitable for a larger company if the goal is to connect locations flexibly and reduce the administrative and operational burden. An on-premises solution may be the right choice for a smaller company if it needs to be integrated into an existing infrastructure or supports specific processes.
It is important not to view telephony in isolation from the network and security. Voice quality depends on stable Internet connections, proper prioritization within the LAN, and a firewall configuration that reliably allows VoIP connections. If there are multiple locations, a plan is also needed for connecting the sites and for dealing with the event that an Internet connection fails.
Set Up Microsoft Teams as a Calling Channel
Many companies use Microsoft Teams for chats, meetings, and files, but still make phone calls using separate systems. This leads to a disruption in the user experience: An employee can see someone’s status in Teams but must use a different device or application to make the call. An integrated solution, on the other hand, turns Teams into a full-fledged telephony channel with a Swiss landline number, an extension, and access to corporate features.
However, not every workstation is the same. Employees at the front desk, in production, or in customer service often need a physical IP phone with clearly visible function keys, a headset jack, and reliable operation. Sales teams and project managers, on the other hand, often work directly in Teams using laptops and smartphones. Both groups should be integrated with the same number, the same call history, and the same availability rules.
Native Teams integration reduces the need for additional components and simplifies operations. Winet connects the Ayrix PBX directly to Microsoft Teams without requiring separate Teams add-ons or SBC components that incur licensing fees. For businesses, this means fewer interfaces, clearer responsibilities, and a telephony system that aligns with existing workflows.
Selecting IP Phones for Workstations Based on Specific Needs
Not every IP phone needs to offer the same features. A standard device for a quiet, individual workstation has different requirements than a phone at the front desk or in a shared area. If you purchase a one-size-fits-all model, you’ll either end up paying for unused features or make day-to-day work more difficult for individual teams.
At the front desk, a clear display, plenty of programmable buttons, and the ability to switch quickly between calls are essential. In the back office, a few phone lines, a good headset, and simple call forwarding are often sufficient. For meeting rooms or common areas, conference phones or specially configured shared profiles may be the better choice.
The network connection also deserves attention. Devices with a built-in Gigabit switch allow you to connect a PC and a phone via a network jack. This saves on cabling but requires a proper network configuration. Power over Ethernet simplifies power delivery and, with an uninterruptible power supply, ensures that critical phones remain available for longer even in the event of a local power outage.
Security and call quality are integral to the project
VoIP is part of the corporate network and must be protected accordingly. An open or incorrectly configured SIP port can result in unauthorized call charges, attack attempts, or service disruptions. Firewall rules, separate VLANs for voice traffic, secure login credentials, and regular updates are therefore not optional.
In more complex scenarios, a session border controller (SBC) can secure the connection between the phone system, the SIP trunk, and external networks. It controls signaling and media streams, supports interoperability, and protects against common VoIP attacks. Whether an SBC is required depends on the architecture. With a fully managed cloud PBX, this task is often handled by the platform; in on-premises or highly integrated environments, a dedicated SBC may be advisable.
Clear calls also require sufficient bandwidth, but above all, stable latency, low packet loss, and prioritized voice traffic. A fast Internet connection alone is no guarantee of good call quality. When large backups or cloud syncs are using up bandwidth, Quality of Service (QoS) rules must prioritize call data.
Clarify phone numbers, processes, and migration early on
The technical transition will only be successful if customers and partners can continue to reach the numbers they are accustomed to. The porting of existing phone numbers should therefore be prepared well in advance. This includes providing complete information about the previous provider, verifying contract terms, and setting a binding switchover date. For critical main numbers, it is recommended to have a clear contingency plan in place in case unexpected issues arise during activation.
At the same time, managers should review the existing call routing. Which number is routed to which group? Who covers for absent staff? How are emergency calls, on-call duties, or evening announcements handled? Many companies carry over old settings without reviewing them and later realize that they no longer fit their current organizational structure.
A successful migration therefore also uses the transition as an opportunity to streamline the system. Direct extensions that are no longer needed are removed, call groups are given clear names, and permissions are documented in a transparent manner. Interfaces to CRM, ERP, LDAP or CTI can then be set up specifically for this purpose, rather than carrying over legacy technical issues into the new environment.
Assess costs realistically and in a way that allows for planning
When implementing an IP telephony project, it’s not just the monthly call rates that matter. You also need to factor in licenses for the phone system, hardware, Internet access, installation, number porting, security components, and support. In return, you often save on costs for old ISDN or analog lines, maintenance contracts for outdated systems, and time-consuming site modifications.
Flat-rate plans offer predictable costs for teams with regular call volumes. Per-minute rates may be more cost-effective for small businesses or lines that are rarely used. The key is to take a transparent look at actual calling behavior, not the supposedly lowest per-minute rate.
A professionally designed IP phone system in the office, above all, provides flexibility: New employees, additional locations, and other work models can be accommodated without having to completely overhaul the system. By first addressing accessibility, processes, security, and integration, you’ll get a telephony solution that takes the pressure off employees and works reliably in the background during customer calls.
Current
Cloud Telephony for Teams That Are Always Reachable
Teams, phone service, or VoIP—which one is right for you?
Choosing a Video Conferencing Solution for Businesses
Choosing the Right Phone System for Remote Teams
Configuring the Session Border Controller Correctly
