Mobile Voice Core Engineer

Our Client are a leading communications brand with an outstanding reputation for customer service and value commitment. An opportunity has now arisen within their team for an experienced Mobile Voice Core Engineer.

Here the Mobile Voice Core Engineer will:

• Ensure the reliable operation, maintenance, and evolution of the Mobile Core network, including CS, EPC, IMS, and associated platforms
• Deliver high availability and performance for Packet Switched (PS) and Circuit Switched (CS) services, supporting technologies such as VoLTE, and 5G Core
• Act as a subject matter expert for IMS-based services (SIP, Cloud Voice, FTTH voice, Microsoft Teams Operator Connect), providing technical support for integration, troubleshooting, and optimization
• Operate and maintain IMS, CS and EPC components, ensuring compliance with KPIs and SLAs
• Monitor, perform configuration, upgrades, and patches for Mobile core network elements (MME, SGW, PGW, PCRF, HSS, HLR, SBC, CS Core and IMS nodes) working with Ericsson and other in-house engineers
• Monitor and analyse performance metrics to optimize capacity and quality of service
• Troubleshoot complex issues across signaling protocols (Diameter, SIP, SS7, HTTPs) and resolve faults promptly
• Manage IMS platforms and SIP-based services for mobile and fixed voice
• Support Cloud Voice and FTTH voice solutions, ensuring seamless integration with IMS
• Implement and maintain Microsoft Teams Operator Connect and related interworking functions
• Ensure QoS and security compliance for all IMS-based services
• Support roaming services and ensure IREG compliance
• Maintain mobile support services such as SMS antifraud, voicemail, and SIM steering
• Support the deployment of new SIP carrier interconnects and ongoing support, routing and troubleshooting of existing interconnects
• Work with the Security Architect to (a) review assets, identify weaknesses and ensure appropriate security is maintained; (b) to ensure the Security strategy is implemented including the integration from within your domain with the company's security technology and tools
• Investigate security alerts and provide incident response within your domain
• If/When potential weaknesses, attacks, intrusions, unusual, unauthorised or illegal activity are identified, assist in the implementation of mitigations, including vulnerability management

The ideal candidate for the role of Mobile Voice Core Engineer will have:

• Strong understanding of 2G, 4G and 5G mobile networking and associated core
• Strong understanding of protocols utilised in a mobile network including but not limited to SIP, Diameter and SS7
• Experience with mobile core nodes (MME, SGW, PGW, PCRF, HSS) and IMS components (SBC, , S-CSCF, I-CSCF BGCF etc)
• Knowledge of IP networks, routers, switches, dynamic routing protocols and an appreciation of system security
• An understanding and skills to configure and administer a telecoms virtualised and containerised environment
• Good communication skills both written and verbal
• Willingness to work and communicate with both internal cross departmental teams as well as external customers
• Flexible approach to work and participation in a callout rota
• Desire to learn new technologies through both formal and self-learning and ability to adapt to an ever-changing technical environment