Network Operations Engineer

The Company

Founded in 2009, Cubic Telecom has grown to become one of the leading providers of connectivity solutions and analytics services that help vehicle and IoT device manufacturers manage and grow revenue streams. Fast paced, smart, ambitious, and continually seeking new, ideas. That’s us, is it you? At Cubic you will find an environment filled with energy and collaboration, where we set out every day to improve not just the world, but ourselves and each other.

The Role

We are looking for an energetic, enthusiastic Network Operations Engineer who is committed to their work and thrives in a fast-paced, highly flexible environment. In this role, you will be a key part of the team ensuring the seamless operation of Cubic Telecom's global connectivity platform, supporting critical services for IoT devices, automotive solutions, and mobile networks.

You will take ownership of troubleshooting and resolving complex network issues, particularly in relation to SS7, Diameter, S6a signalling, VoLTE, SMS, and CS voice. Your day-to-day will involve proactive monitoring, deep technical analysis, and the use of advanced diagnostic tools to identify and address problems related to network attach failures, data session setup issues, and performance inconsistencies during roaming scenarios.

Collaboration is key in this role. You’ll work cross-functionally with internal engineering teams, external vendors, and MNO partners to resolve issues efficiently and ensure minimal disruption to services. You’ll also contribute to continuous improvement initiatives by sharing knowledge, mentoring colleagues, and refining operational processes to enhance service quality and network stability. You will be encouraged to develop innovative solutions, participate in cross-team problem-solving, and actively engage in efforts to optimise network performance.

Responsibilities of this role:

• Support the introduction of new services, ensuring they meet technical and performance standards.
• Work closely with Cubic vendors to ensure timely delivery and optimal performance of services.
• Proactively monitor and troubleshoot network issues, particularly with 3G/LTE attach failures, data session setup in roaming scenarios, and app-specific data throughput inconsistencies, ensuring minimal disruption to Cubic customers.
• Collaborate with internal stakeholders and customers to promptly resolve service-affecting issues.
• Conduct deep technical investigations using protocol analysis tools (e.g., Wireshark) to identify and resolve signalling and data session-related problems.
• Work with MNO partners to facilitate the seamless introduction of new services, including managing configurations and troubleshooting signalling issues during service deployment.

• Support team members by sharing knowledge and expertise, mentoring less experienced colleagues on signalling protocols and troubleshooting methodologies.

• Where necessary, schedule and execute network maintenance activities, including upgrades and migrations, to ensure ongoing network health.
• Lead incident resolution efforts, especially for escalated cases involving complex signalling issues or roaming-related problems, performing root cause analysis and implementing long-term fixes.
• Continuously improve operational processes by reviewing and refining troubleshooting workflows and documenting lessons learned from incidents, enhancing both team efficiency and service reliability.
• Support the enforcement of change, release, incident, and problem management processes to ensure consistency, minimise service disruptions, and maintain network stability.

• Minimum of 4 years’ experience working in the core network domain.
• Strong knowledge of SS7 protocol to diagnose and resolve signalling issues.
• Familiarity with Diameter signalling, particularly the S6a interface for handling authentication, authorisation, and mobility management.
• Experience diagnosing VoLTE-related call drops, quality issues, and troubleshooting SIP signalling in IMS networks and an ability to troubleshoot issues in traditional CS voice networks, including handover failures, call drops, and quality concerns.
• Deep understanding of SMS signalling, including delivery issues, message routing, and troubleshooting MT/MO message failures.
• Knowledge of mobile roaming solutions and related technologies, including, a solid understanding of 3G and LTE attach procedures, especially in roaming scenarios.
• Experience in resolving location update failures and authentication problems.
• Expertise in diagnosing PDP context setup issues, identifying problems with APN configuration, DNS resolution failures, and identifying conflicts in P-GW/GGSN configurations during roaming.
• Proven ability to troubleshoot inconsistent data throughput for specific apps during roaming scenarios, including firewall issues, MTU mismatches, or misconfigured application-layer protocols.
• Ability to quickly comprehend internal Core network call-flows or map out undocumented call-flows step by step, tracing each hop to ensure a clear understanding
• Ability to use tools like Wireshark, tcpdump, or similar to analyse signalling traffic and diagnose protocol-specific issues across SS7, Diameter, GTP, and SIP layers.
• Experience working with external vendors to escalate complex issues, provide logs, traces, and collaborate on fixes for signalling or session-related problems.
• Familiarity with network monitoring and performance management tools (e.g., Zabbix, PRTG, SolarWinds) to detect and troubleshoot network issues proactively.
• Strong documentation skills for incident reports and post-incident root cause analysis, with an ability to break down complex problems into digestible reports.

Desired Experience and Qualifications

• Understanding of underlying IP network architecture and the ability to perform initial issue analysis.
• Experience with ITIL processes is an advantage.
• Familiarity with multi-IMSI solutions, and eUICC SIM profile downloads