The Packet Core Test Engineer will be responsible for the end-to-end testing and validation of our GPRS, LTE, and 5G packet core network. This role involves designing test strategies, executing complex test cases, and analysing results to ensure the network's functionality, performance, scalability, and security. The ideal candidate possesses a deep understanding of mobile data traffic protocols and has hands-on experience with key packet core network elements.

Key Responsibilities

• Test Planning & Strategy: Develop detailed test plans and strategies for new features, network integrations, node upgrades, and capacity expansions in the packet core environment.
• Test Execution: Perform functional, integration, system, regression, and performance/load testing on packet core network elements, including:
  • 4G: MME, SGW, PGW, PCRF/PCF
  • 5G: AMF, SMF, UPF, AUSF, UDM/UDR, NRF, PCF
  • Common: DRA, DNS, NTP
• Protocol Analysis: Utilise protocol analysers (e.g., Wireshark) to capture and decode key protocols such as GTPv2-C, GTPv1-U, PFCP, DIAMETER, S1AP, NGAP, NAS, and HTTP/2 to diagnose data session issues.
• Lab Environment Management: Configure and maintain a complex packet core test lab, including setting up network simulators (e.g., UEs, RAN) and traffic generators.
• Defect Management: Identify, document, and track defects through to resolution using issue tracking systems like JIRA. Collaborate with design and development teams to troubleshoot and verify fixes.
• Performance Benchmarking: Conduct load, stress, and high-availability tests to measure key performance indicators (KPIs) like throughput, latency, session setup success rate, and capacity limits.
• Automation: Develop and maintain automated test scripts using tools and languages (e.g., Python, Tcl, Robot Framework, Spirent/IXIA APIs) to automate regression and feature testing.
• Documentation: Create detailed test reports, Method of Procedures (MOPs), and knowledge base articles.
• Collaboration: Work closely with R&D, architecture, and operations teams to ensure the delivery of a high-quality network.

Required Qualifications & Skills

• Bachelor’s degree in Telecommunications, Electrical Engineering, Computer Science, or a related field.
• 3+ years of hands-on experience in testing and validating 4G and/or 5G packet core networks.
• In-depth knowledge of packet core architecture and call flows (e.g., LTE Attach, PDN Connection Establishment, 5G Registration, PDU Session Establishment).
• Strong expertise in core mobile data protocols: GTP (v1-C, v2-C, v1-U), PFCP, DIAMETER, S1AP, NGAP, and NAS.
• Proven experience with protocol analysis tools like Wireshark (must-have) and other troubleshooting tools.
• Hands-on experience with test tools and traffic generators such as Spirent Landslide, Ixia BreakingPoint, SARA, or similar.
• Solid understanding of IP networking fundamentals (TCP/IP, routing, switching, VLANs, firewalls).
• Experience in creating detailed test plans, test cases, and defect reports.
• Strong analytical and problem-solving skills with a meticulous attention to detail.
• Excellent verbal and written communication skills.

Preferred Qualifications

• Experience with 5G Core (5GC) and Standalone (SA) architecture.
• Programming/scripting skills for test automation (e.g., Python, Bash, Tcl, Robot Framework).
• Experience with cloud-native technologies and containerization (e.g., Kubernetes, Docker, OpenStack) and testing VNFs/CNFs.
• Knowledge of network security principles within the packet core (e.g., firewall policies, DDoS protection).
• Understanding of policy control (PCRF/PCF) and charging functions (OCS, OFCS).
• Familiarity with 3GPP standards related to the packet core.
• Experience working in an Agile/Scrum environment.