IMS Component Test Engineer (mfd)

Role Overview

We are looking for anIMS Component Test Engineerto design execute and optimizeisolated testing of individual IMS network componentssuch asP-CSCF S-CSCF I-CSCF and IMS Application Servers.

The role focuses onprotocol-level validation load behavior and resource efficiency usingSIPp-based SIP emulationandDiameter emulatorsto simulate dependent IMS interactors. All IMS components arecontainerised and deployed on Kubernetes.

The engineer will work closely with platform core network and performance teams to ensure each IMS component behaves correctly efficiently and predictably under both functional and stress conditions.

Key Responsibilities

IMS Protocol & Call Flow Testing

• Performindividualcomponent-level testingof IMS elements (P-CSCF S-CSCF AS etc.) in isolation

• Provide actionable insights to improveIMS robustness scalability and efficiency

• Analyze and troubleshootSIP Diameter and mixed-protocol call flows

SIPp-Based Emulation & Load Testing

• Design and maintain SIPp XML scenario files for IMS signaling use cases

• Correlation between multiple SIPp scripts to keep traffic realistic for the system under test

• Create input CSV files and dynamic data injection for large subscriber sets

• Emulate IMS interactors using SIPp (UEs proxies application servers)

• Execute bulk-load CPS and long-duration endurance tests

• Model real world traffic on individual IMS components from Wireshark captures

• Capture inspect and analyze pcaps for SIP signaling validation

Observability & Resource Analysis

• Monitor IMS component performance usingGrafana dashboards

• Analyze:

  • CPU memory network and socket utilization

  • Max traffic capacity

  • Latency under load

• Correlateprotocol-level behaviorwithresource consumption

• Identify bottlenecks leaks or inefficiencies during prolonged runs

Valuable Skills

These skills will significantly improve the effectiveness of individual IMS component testing:

IMS & Telecom-Specific

• Understanding of3GPP IMS call flows

• Knowledge oftimers retransmissions and failure scenarios

• Familiarity withENUM / DNS / NAPTRin IMS routing

• Exposure toKamailio / OpenSIPS

Kubernetes & Platform Awareness

• Basic Kubernetes troubleshooting

• Awareness of how container limits affect SIP/Diameter performance

• Work-Life-Balance is a priority: Flexible working that suits you - we live and breathe a hybrid remote culture and dont mind where and when you work
• We are committed to building a diverse team that represents a variety of backgrounds perspectives and skills in a traditionally not very diverse industry
• We offer you the culture of a fast-growing start-up with the maturity of an enterprise company
• We are more interested in your experience and knowledge than formal degrees
• Entrepreneurial culture and flat hierarchies
• Mobility benefit fitness benefit language class benefit and wellness benefit (for full-time employees)
• Home office budget (for full-time employees)