As the global rollout of 5G accelerates, telecom operators face important choices between Non-Standalone (NSA) and Standalone (SA) deployment models. Each model offers distinct advantages, challenges, and implications for network security. In this comprehensive guide, we dive deeper into the critical differences, explore potential vulnerabilities, highlight best practices, discuss real-world scenarios, and examine future trends to secure both deployment scenarios effectively.
Understanding Non-Standalone (NSA) 5G Architecture
Non-Standalone (NSA) 5G leverages existing 4G LTE infrastructure, integrating the 5G New Radio (NR) technology with the legacy Evolved Packet Core (EPC). NSA enables rapid deployment of 5G services by maintaining existing LTE components for control signaling and session management, allowing operators to offer enhanced data rates and capacity with minimal infrastructure investment.
Real-world NSA Deployments
Early adopters such as Verizon and AT&T initially employed NSA to expedite their 5G rollout. This allowed quick market entry but also highlighted legacy security risks associated with the 4G LTE core.
Case Study: NSA Deployment Vulnerabilities
In 2021, several European operators experienced service disruptions due to Diameter-based attacks exploiting NSA deployments. These attacks revealed critical gaps in legacy signaling infrastructure, leading to service outages and raising awareness about inherent NSA vulnerabilities.
Security Risks Associated with NSA 5G
NSA inherits vulnerabilities present in the existing LTE network, exposing operators to a variety of legacy threats:
- SS7 and Diameter Protocol Attacks: Exploits can lead to location tracking, call interception, and fraud.
- GTP Protocol Vulnerabilities: Attackers may perform injection attacks, causing denial-of-service conditions or unauthorized access.
- SIM Swapping and IMSI Catchers: NSA’s reliance on legacy authentication mechanisms makes it susceptible to subscriber identity theft and interception.
These persistent issues underline the need for immediate and robust protective measures.
Securing NSA Deployments: Best Practices
Operators must implement stringent controls to mitigate these inherited risks:
- Deploy Enhanced Firewalls: Use signaling firewalls specifically designed for SS7, Diameter, and GTP to block malicious signaling messages.
- Advanced Intrusion Detection Systems (IDS): Deploy telecom-specific IDS solutions to monitor and analyze signaling traffic, identifying anomalies indicative of cyber threats.
- Continuous Monitoring and Auditing: Regularly audit and retire outdated network components and configurations that pose security risks.
Exploring Standalone (SA) 5G Architecture
In contrast, Standalone (SA) 5G introduces a fully cloud-native, independent 5G Core, decoupled entirely from legacy 4G LTE infrastructure. This advanced architecture utilizes a Service-Based Architecture (SBA), built upon modern protocols such as HTTP/2 and OAuth2, enabling comprehensive security measures, stronger authentication, and support for advanced features like network slicing.
Real-world SA Deployments
Countries like South Korea and operators such as T-Mobile US have moved aggressively towards SA deployments, capitalizing on improved security, flexibility, and support for emerging 5G use-cases like IoT and private networks.
Case Study: Successful SA Security Implementation
T-Mobile US successfully implemented SA 5G security using advanced zero trust principles and network slicing. Their robust SA security strategy minimized risks related to API exposure and virtual network functions, demonstrating best practices in modern telecom security.
Security Considerations in SA Deployments
Despite enhanced security capabilities, SA introduces new security challenges:
- API and Microservices Exposure: APIs within the SBA present new attack surfaces vulnerable to misconfigurations and exploits.
- Virtualization and Cloud Risks: Containers and virtual network functions introduce risks like container escapes, insecure orchestration, and vulnerable dependencies.
- Misconfiguration and Insider Threats: Complexity and flexibility of SA increase the potential for human errors and intentional insider threats.
Safeguarding Standalone (SA) Networks: Key Strategies
Operators must adopt modern cybersecurity practices tailored specifically to SA 5G:
- Zero Trust Implementation: Adopt comprehensive zero trust policies that require explicit authentication for every transaction and service interaction.
- API Security Enforcement: Secure API gateways, utilize strong authentication protocols, and regularly audit and manage API traffic.
- Runtime Security and Container Protection: Implement real-time threat detection, behavior analytics, and automated mitigation solutions to safeguard cloud-native functions.
- Hardware Security Modules (HSM): Utilize HSMs for secure key management, authentication, and encryption.
Transitioning from NSA to SA: A Secure Path Forward
As operators shift from NSA to SA, security transitions must be carefully managed:
- Protocol Modernization: Gradually retire legacy protocols and enforce security measures aligned with the SA model.
- Secure Roaming and Interconnect: Enhance interconnection security through protocols such as SEPP, protecting roaming interfaces from potential threats.
- Integrated Monitoring: Consolidate security monitoring platforms to cover both legacy and new 5G infrastructure seamlessly.
Future Trends: The Road Ahead for NSA and SA
The evolution from NSA to SA is expected to accelerate, driven by emerging use-cases demanding lower latency, higher security, and more customized network experiences. The telecom industry anticipates widespread adoption of cloud-native architectures, AI-driven network security, and automated security management as critical pillars supporting future SA networks.
Conclusion
The transition from NSA to SA represents a critical evolutionary step for mobile operators, offering both substantial advantages and significant security considerations. Understanding these distinct security landscapes and implementing appropriate protective strategies will determine operators' long-term success and resilience.
