IP Network Packet & Voice Core Design Engineer

ECS Resource Group are currently working in partnership with a global managed service provider, assisting them with the search for a IP Network Packet & Voice Core Design Engineer on a contract basis.

• Design and deliver end-to-end IP transport connectivity across Packet and Voice Core network elements within a mobile core environment
• Lead technical discussions to define IP connectivity requirements for multiple traffic flows and protocols between core network functions
• Produce high-level and low-level design documentation, including traffic flow models and detailed parameter assignments
• Develop and review firewall communications matrices, methods of procedure (MOPs), and configuration scripts in collaboration with security and operations teams
• Implement network solutions (including out-of-hours changes) and lead fault investigations to resolve complex connectivity issues

• Strong expertise in Packet Core and 5G Standalone (5G SA) architectures, including protocols such as DIAMETER, SIGTRAN, RADIUS, GTP, and S1-U
• In-depth knowledge of Voice Core network elements and protocols, including SIP, DIAMETER, and SIGTRAN
• Excellent understanding of IP networking technologies, including IPv4/IPv6, BGP, OSPF, MPLS, IPSEC, VXLAN, and LACP
• Hands‑on experience with enterprise networking platforms, firewalls, load balancers, and network analysis tools
• Strong analytical and communication skills, with the ability to trace IP traffic end‑to‑end and present technical designs to stakeholders

Further job details available upon request.

Please note, due to internal capabilities it will be difficult for us to take internal calls regarding your application – please direct all queries to , and they will be responded to, alongside your application ASAP. If you haven’t received a response within 1 working day, please call the direct line which is .