Failures and Resilience in the IP Era: Navigating the Fragility of Modern Telecommunications Networks—The Sovereign Functions

Telecommunications networks have become critical infrastructure, with increasing reliance on their continuous availability driven by expectations of uninterrupted connectivity, real-time communication, and a surge in connected devices across both consumer and industrial domains. Over time, industrial systems and machine-to-machine applications have transitioned from isolated, purpose-built infrastructures to shared, general-purpose IP-based networks. While this evolution has enabled greater flexibility and integration, it has also introduced operational complexity and new classes of failure. Although physical layer redundancy and geographic isolation remain essential components of network resilience, modern networks are heavily dependent on a set of interdependent IP functions. These include routing, addressing & naming services, and time synchronisation—each playing a sovereign role in end-to-end service continuity. Importantly, these functions are increasingly coupled with a range of supporting services—such as authentication & access control, license management, and network configuration & management—which, while not formally specified within the IP protocol suite, are essential to its operation and resilience. This paper presents a failure-centric survey of sovereign and supporting functions in modern telecommunications networks, illustrating how real-world outages often stem from failures in these interdependent layers, which form the organising lens for this study. Through detailed case studies, we illustrate the severe consequences of such failures on network services, along with their broader economic and corporate ramifications. Furthermore, we explore potential mitigation strategies and emphasize the need for continued research to develop more resilient network architectures capable of withstanding inherent vulnerabilities in IP-based systems. This study contributes to enhancing service resilience amid the growing complexity and demands of modern mobile and fixed networks.