This list contains only the countries for which job offers have been published in the selected language (e.g., in the French version, only job offers written in French are displayed, and in the English version, only those in English).
We are looking for an expert engineer to lead the design, deployment, and expansion of our Packet Switched (PS) Core Network. This is a hands-on role that bridges the gap between high-level network architecture and low-level protocol analysis. You will take ownership of the core network evolution, supporting legacy 3G, dominant 4G LTE, and emerging 5G NSA architectures. You will work closely with vendors to define requirements, validate solutions, and ensure a seamless rollout and operation of critical network functions.
Job Responsibility:
Design and dimension the Packet Core (EPC/5GC) to ensure scalability for data growth
Manage roaming coverage with IPX/GRX providers, roaming sponsors, and direct bi-lateral agreements
Define specific network profiles and configurations for HSS/UDM subscribers, including QoS, AMBR, and APN subscriptions
Architect the DNS hierarchy for the mobile core, focusing on S-NAPTR records for MME/SGSN to discover PGW/SGW/UPF nodes
Plan and implement IP routing strategies, including ASN (Autonomous System Number) management and BGP peering for internet and roaming connectivity
Manage Access Point Name configurations for various service types, including IMS, Internet, and IoT
Perform deep-dive troubleshooting of signaling procedures across 3G (Iu-PS), 4G (S1-MME, S11, S5/S8), and 5G NSA (EN-DC)
Apply in-depth understanding of 3GPP standards for 3G, 4G EPC, and 5G NSA mobile data call-flows
Analyze and optimize critical flows, specifically Attach/Registration (Authentication vectors, ULR/ULA, Create Session) and Bearer Management (Dedicated bearer creation for VoLTE/QCI 1 and default bearers)
Utilize protocol analyzers such as Wireshark or Tektronix to decode ASN.1 based messages and Diameter signaling (Gx, Gy, S6a, S5, S8, GTP-C, GTP-U)
Act as the primary technical interface with core network vendors, system integrators, and partners
Lead technical evaluations and design reviews for core network expansions
Manage the ATP (Acceptance Testing) phase to ensure vendor deliveries meet operational standards prior to live deployment
Requirements:
Experience with a Tier 1 Carrier, Mobile-Operator, or Major Network Equipment Provider (NEP) background
Deep understanding of SGSN, GGSN, and HLR architecture
Extensive experience with PGW, HSS, SGW, and MME
Proficiency in 5G Non-Standalone (NSA), 5G Standalone (SA), and PCC
Hands-on experience with Diameter S6a (HSS-MME), Gx (PCRF-PGW), and Gy (OCS-PGW)
Strong knowledge of IP addressing, subnetting, OSPF/BGP routing, VRFs, and ASN management
Expert-level DNS resolution (A, AAAA, SRV, NAPTR), DHCP, and IPX/GRX management
Nice to have:
Experience managing inbound/outbound roaming via Sponsor IMSI providers
Technical knowledge of GTP-Proxy deployments for signaling and payload optimization
Practical experience working within an MVNO or MVNE environment
Familiarity with Regional and Local Breakout (LBO) strategies to reduce latency
Experience with Cloud Native Network Functions (CNF) and containerized core deployments
What we offer:
Health Insurance
work-from-anywhere stipend
annual wellness & learning credits
annual all-expenses-paid company retreat in a gorgeous destination & other benefits