Navigating the 2G Sunset: Modernizing Signaling While Maintaining Legacy Interworking

As telecommunications operators worldwide continue to modernize their networks, the retirement of second-generation (2G) mobile technology is becoming an increasingly important part of their network strategies. Driven by the need for greater spectrum efficiency, improved security and more flexible network architectures, operators are announcing timelines for switching off legacy mobile networks.

A prominent example is Dutch telecommunications provider KPN, which has announced that it will switch off its 2G network on December 1, 2027. While most consumer mobile traffic has long since migrated to 4G and 5G, a significant number of enterprise devices and IoT applications—including smart meters, industrial sensors, alarm systems and automotive components—still depend on 2G connectivity.

For operators, managing this transition involves more than simply switching off an older radio technology. They must identify dependencies, migrate affected services and modernize their underlying network infrastructure without compromising connectivity and service continuity.

The Persistent Need for Legacy Signaling

Retiring a 2G radio access network (RAN) does not automatically eliminate the need for legacy signaling protocols. Although the number of applications relying on older mobile technologies continues to decline, SS7 remains relevant in parts of the telecommunications ecosystem, including legacy interworking, roaming-related services and networks that have not yet completed their migration to newer technologies.

Several factors contribute to this continuing requirement:

• Long IoT Lifecycles: Utility, transport and industrial IoT deployments often involve devices designed to operate for many years. Replacing or upgrading these devices can take considerable time and investment. Operators and service providers must accommodate different generations of connectivity during migration.
• International Roaming and Interworking: Countries and operators are retiring legacy technologies at different speeds. Even after switching off their own 2G networks, operators may need to maintain SS7 signaling capabilities for legacy interworking and connections with networks that still operate older technologies.
• Legacy Service Dependencies: Certain enterprise, M2M and international connectivity services continue to rely on established signaling protocols. Identifying these dependencies and ensuring service continuity is an important part of any network retirement strategy.

This creates an important distinction between retiring legacy radio access and modernizing the signaling infrastructure that supports the wider mobile ecosystem.

At the same time, many operators face the challenge of maintaining aging, proprietary Signal Transfer Point (STP) infrastructure. Some existing installations are approaching vendor end-of-support, resulting in increasing maintenance costs, operational risks and limited flexibility when integrating with modern network architectures.

Bridging the Multi-Generational Gap

The industry needs an approach that rationalizes legacy signaling infrastructure while supporting the transition towards modern, software-defined networks.

Rather than maintaining separate signaling platforms for different technology generations, operators can adopt unified signaling solutions that support SS7 (2G/3G), Diameter (4G) and HTTP/2-based interfaces used in the 5G Service-Based Architecture.

BFX Unified Signaling Core

This converged approach enables operators to consolidate signaling functions within a common software platform, reducing dependence on separate proprietary hardware systems.

By deploying STP functionality on virtualized or containerized infrastructure, operators can retain essential SS7 routing capabilities while moving away from aging physical appliances. The result is a more flexible architecture that can integrate with modern cloud environments and support the coexistence of legacy and next-generation network technologies.

Importantly, this does not mean retaining obsolete 2G services indefinitely. It means modernizing the infrastructure that remains necessary while allowing individual network technologies and services to be retired in a controlled manner.

Industry Recognition for Cloud-Native Signaling

The importance of modernizing legacy signaling infrastructure was recognized at MWC Barcelona in 2025, when signaling specialist BroadForward received the GSMA GLOMO award for Best Digital Tech Breakthrough for Companies with Under $10million Annual Global Revenue.

The award recognized BroadForward’s World First Cloud-Native Signaling Transfer Point (STP).

The GLOMO judges described the solution as:

“An elegant and innovative solution to a legacy problem of critical voice networks – fulfils an immediate market need.”

The award highlights an important industry development: operators no longer need to depend exclusively on traditional proprietary hardware to maintain essential signaling capabilities.

BroadForward’s cloud-native STP provides a software-based alternative to aging STP infrastructure, supporting migration towards more flexible, scalable and cost-efficient network architectures.

As part of its broader BFX Unified Signaling Core, BroadForward also supports Diameter and 5G signaling functions, enabling operators to consolidate multiple generations of signaling within a common software framework.

This provides a practical migration path for operators seeking to modernize their signaling infrastructure without compromising the legacy interworking capabilities they still require.

Strategic Outlook for Operators

The phase-out of 2G is part of a broader transformation towards more efficient, flexible and cloud-oriented telecommunications networks. However, successful sunset strategies require operators to look beyond the radio access network and understand the dependencies that remain within their core infrastructure.

Three priorities stand out:

• De-risking the RAN Sunset: Identify and migrate enterprise, IoT and other services that still depend on 2G. Allow sufficient time for device replacement, integration and operational testing.
• Consolidating Signaling Infrastructure: Replace aging, single-purpose signaling appliances with unified software platforms capable of supporting multiple generations of mobile network protocols.
• Adopting Flexible Deployment Architectures: Move essential signaling functions to virtualized or containerized infrastructure, enabling greater scalability, easier lifecycle management and integration with modern cloud environments.

The retirement of 2G does not mean the immediate disappearance of legacy signaling. Instead, it creates an opportunity to rethink how operators manage the infrastructure that connects different generations of telecommunications networks.

Those that successfully separate essential signaling capabilities from outdated proprietary hardware will be better positioned to simplify operations, strengthen network security and prepare their infrastructure for the continued evolution towards 5G Standalone and future 6G networks.