Across the world, the Public Switched Telephone Network (PSTN)—once the standard for business voice—is being phased out. Countries like Germany and the Netherlands have already completed their transitions, while others like the UK and Singapore are actively winding down copper-based systems in favor of modern, cloud-native voice infrastructure.
For telecom providers, this presents an opportunity to build something better.
From Legacy to Modern: The Current Landscape
In the UK, the PSTN shutdown is scheduled for January 31, 20271. In Germany, over 95% of all new business phone system deployments in 2023 were SIP-based by default2. North America shows similar momentum, with 65% of organizations using SIP trunking and over 18 million active lines in use3. In India, enterprise SIP deployments grew 48% year-over-year, highlighting strong growth across the Asia-Pacific region.
The global SIP trunking market—a core component of modern voice—is expected to grow from US$80.8 billion in 2025 to US$255.4 billion by 2034, with a CAGR of nearly 14% (Market Research Future). Another forecast places it at US$177.8 billion by 2032, up from US$54.2 billion in 20235.
PSTN shutdowns affect more than voice. Systems like security lines, fire alarms, and payment terminals often rely on the same infrastructure, making modernization a broader operational concern. As copper networks age, maintaining service quality becomes more difficult. This moment provides an opportunity to implement infrastructure that is more resilient, flexible, and built for long-term demands.
Why Cloud Voice Is the Next Logical Step
Modernizing PSTN systems goes beyond maintaining connectivity; it creates the foundation for more adaptable and integrated voice services.
PSTN relies on physical copper lines and centralized switches, designed for a time when communications were fixed-location and hardware-based.
SIP (Session Initiation Protocol) enables software-based systems that run over the internet. This shift introduces key advantages for providers building toward more agile, future-ready voice systems.
Key Advantages of SIP for Providers:
- Scale without new infrastructure
Traditional PSTN networks require physical expansion—new lines, switchboards, and site visits—to grow. With SIP, scaling is virtual. Providers can onboard new users, launch services in new regions, or add features without touching hardware. It also allows service providers to respond to customer needs faster, reducing lead times from weeks to hours and creating a more agile, responsive communications environment.
- Smarter Service Delivery
In addition, SIP-based systems come with modern capabilities that enhance the customer and operational experience. Features like intelligent call routing, call queuing, voicemail-to-email, auto-attendants, and call analytics are built in and centrally managed. Providers gain visibility into how services are being used and can make real-time adjustments—without needing manual intervention or hardware replacements. It transforms telephony from a static utility into a dynamic, data-informed service layer.
- Lower operational cost
Hosted PBX solutions shift voice services from capital expenditure to operating expense. There’s no need for on-site switching gear or dedicated telco rooms—maintenance, upgrades, and security patches happen in the cloud. This reduces IT overhead, eliminates the costs tied to equipment upkeep and replacement cycles, and cuts support hours spent managing legacy hardware. Providers also benefit from more predictable monthly costs and higher service availability.
- Support for modern workstyles
Increasingly, today’s teams work from anywhere—offices, homes, airports, or co-working spaces. SIP systems are designed for this flexibility. They support softphones, browser-based calling, mobile integrations, and device handoffs that keep communication seamless regardless of location. This not only improves productivity but ensures businesses remain reachable across channels. For providers, it’s an easy way to offer mobility as a core feature, not an afterthought.
Why Are Some Providers Lagging?
If the global direction is clear, why are some telecom providers slower to move? In many cases, it’s not due to resistance, but real structural constraints.
- Legacy infrastructure is deeply embedded
Many regional providers still rely on hardware-based switching and proprietary provisioning systems that weren’t designed to evolve quickly. Modernizing means more than a software upgrade, it’s a full architectural rethink.
- Cloud-native expertise is still unevenly distributed
While large telecoms may have internal DevOps or engineering teams focused on SIP and hosted services, many mid-sized or niche players don’t. Building cloud voice platforms from scratch is expensive, time-consuming, and outside their core strength.
- White-labeled options haven’t always been accessible
Until recently, many providers felt they had to choose between building their own stack or handing over control to third-party UCaaS platforms. Neither option felt aligned with their long-term strategy or customer relationships.
- There’s caution around regulatory complexity
Especially in markets where cross-border compliance, data sovereignty, or lawful interception are concerns, providers have been understandably hesitant to rush change without clarity or support.
These are valid concerns—but they are increasingly addressable. With the right partners, providers can modernize on their terms, without sacrificing control or compliance.
What We’re Building Toward
In parallel to these shifts, we’ve been focused on what this transition means in practice for infrastructure providers and the partners they support. What we’ve seen is consistent: what used to be a forward-looking consideration is now a core part of how voice services are delivered. Telecoms, CX vendors, and business platforms are all under pressure to modernize voice, and to do it in ways that respect local regulations, budget constraints, and evolving customer expectations.
Our own infrastructure efforts have focused on supporting that shift: building systems that reduce time-to-deploy, support flexible branding, and operate across multiple regulatory environments.
ULAP Voice: Part of the Infrastructure Response
As the industry continues its shift toward SIP and hosted voice systems, our infrastructure efforts have focused on building platforms that support this transition with clarity and efficiency.
ULAP Voice is part of a broader hosted PBX infrastructure designed to align with existing telecom and service environments. It’s structured to reduce operational complexity while supporting flexibility in branding, configuration, and regional deployment.
What we’ve prioritized:
| Rapid deployment | Systems that can be provisioned quickly to support evolving market needs. |
| Brand-ready structure | A framework that accommodates partner branding and integrates with broader service stacks. |
| Regional resilience | Architecture that supports operations across markets, while meeting local compliance requirements. |
| Enterprise-grade capabilities | Advanced routing, call analytics, softphone readiness, and multi-location support are foundational—not add-ons. |
Rather than reinventing what already works, the goal has been to build adaptable infrastructure that aligns with how providers operate today—and where they want to go next.
Looking Ahead
The transition away from PSTN is more than a milestone in telecom history. It signals a broader shift toward communications infrastructure that is more distributed, intelligent, and responsive to real-world business demands.
For providers planning their next move, the focus isn’t only on technology—it’s on finding an approach that balances scale, flexibility, and readiness for what’s next.
Article references:
1 BT Group: Your Guide to the PSTN Switch Off
2 Market Growth Reports: SIP Trunking Services Market
3 SNS Insider: SIP Trunking Services Market
