Business communication has undergone a significant transformation over the last few decades. What began with traditional desk phones and isolated PBX systems has evolved into cloud-based platforms that combine calling, meetings, messaging and collaboration into a single experience. As organisations adapt to remote work, hybrid teams and global operations, the demand for flexible and unified communication solutions has never been greater.
At the centre of this evolution is Microsoft Teams, now widely adopted as a core collaboration platform. However, for Teams to fully replace legacy phone systems, it must connect seamlessly to the public telephone network. This is where SIP trunking plays a very important role bridging traditional voice services with modern unified communications. Together, SIP trunking and Microsoft Teams represent the next stage of enterprise communications.
From Traditional Telephony to Unified Communications
Historically, business voice communication relied on analogue lines or ISDN circuits connected to on-premises PBX systems. While reliable, these systems were costly to maintain, difficult to scale and limited to voice-only functionality. Expanding capacity required physical infrastructure changes and supporting remote workers was often complex.
As IP networks matured, businesses began shifting toward Voice over IP (VoIP), paving the way for more flexible communication models. Unified Communications (UC) emerged as a concept that brought voice, video, messaging, presence and collaboration together under one platform. Microsoft Teams has become a leading example of this approach, enabling employees to communicate and collaborate from virtually anywhere.
Yet, native PSTN connectivity remains a requirement for most organisations making SIP trunking an essential component of a complete UC strategy.
Understanding SIP Trunking in the Modern Workplace
SIP trunking uses the Session Initiation Protocol to deliver voice and real-time communications over IP networks rather than traditional phone lines. Instead of managing multiple physical circuits, businesses can route calls over their existing internet connection using virtual SIP channels. This approach provides clear advantages, including scalability, cost efficiency and geographic flexibility. Organisations can increase or decrease call capacity based on demand and support multiple sites or regions without additional infrastructure.
Providers like Wavetel Business deliver enterprise-grade SIP trunking services designed to integrate seamlessly with modern collaboration platforms, ensuring consistent call quality, reliability and regulatory compliance.
Microsoft Teams as an Enterprise Phone System
Microsoft Teams is widely recognised for meetings, chat and file sharing, but with the right configuration, it also functions as a full enterprise phone system. Through Teams Direct Routing organisations can connect their SIP trunks directly to Teams using certified Session Border Controllers (SBCs). Direct Routing allows businesses to bypass Microsoft Calling Plans and instead use their preferred SIP provider. This flexibility is especially valuable for organisations that want to retain existing phone numbers, manage complex call routing or optimise voice costs.
By combining Teams with SIP trunking from providers such as Wavetel Business organisations gain a unified platform where internal collaboration and external voice communication coexist seamlessly.
SIP Trunking Beyond Voice: Supporting Unified Communications
While SIP is commonly associated with voice calls, its role extends far beyond basic telephony. SIP is designed to establish and manage real-time sessions of various types, including multimedia and presence information. In a Teams environment, SIP trunking enables voice to integrate naturally with meetings, chat and collaboration workflows.
For example, users can escalate a Teams chat into a voice call, join meetings from the same interface or manage all communication from a single device. SIP connectivity ensures that external calls are not isolated from these workflows but are part of the broader UC experience.
Additionally, SIP trunking supports integration with business applications such as CRM systems, analytics tools and service platforms enabling features like click-to-dial, automated call logging and unified reporting.
Considerations for Teams and SIP Integration
A successful Teams Direct Routing deployment relies on a well-designed architecture. Key components include Microsoft Teams Phone System, SIP trunks and certified SBCs that securely connect Teams to the PSTN. Security, resiliency and scalability are critical considerations. Encryption, access controls and SBC protection layers help safeguard voice traffic, while redundancy and failover routes ensure business continuity. Many organisations also adopt hybrid models, allowing legacy PBX systems to coexist with Teams during phased migrations. Working with experienced providers such as Wavetel Business helps organisations design architectures that align with best practices and long-term communication goals.
Real-World Business Impact
The convergence of SIP trunking and Microsoft Teams delivers tangible benefits across the organisation. Employees gain a consistent communication experience across desktop, mobile and remote environments, improving productivity and collaboration. IT teams benefit from simplified management and faster provisioning compared to traditional telephony. From an operational perspective, per-channel SIP pricing often proves more cost-effective than per-user calling plans, especially for organisations with variable call volumes. Built-in resiliency and cloud-based infrastructure also enhance business continuity, ensuring communication remains available during disruptions.
The Future of Business Communications
As business communications continue to evolve, the integration of SIP trunking with Microsoft Teams represents a practical and future-ready approach. It allows organisations to modernise voice services without sacrificing flexibility, control or reliability. While fully embracing unified communications. With the right strategy and the support of trusted providers like Wavetel Business organisations can build a scalable, secure and collaborative communication environment that meets the demands of today’s digital workplace and tomorrow’s growth.
