Core Network Security Engineer (Signaling & Roaming)

Design and implement signaling-security controls (SS7/Diameter/SIP) to reduce roaming exposure, fraud risk, and attacks, delivering evidence and operational handover to SOC/NOC.

• Define signaling-security architecture and baseline policy/rule sets (permit/deny, anomalies, rate limits)
• Analyze roaming vulnerabilities and risks; design mitigations and validate effectiveness
• Coordinate security tests (abuse cases, simulations) and fine-tune rules to minimize false positives
• Integrate events/telemetry with monitoring/SIEM platforms and define actionable alerts
• Develop MOPs with rollback and operational runbooks for the security team
• Support cutovers and post-implementation validations (hardening, route verification)

• Strong practical experience in SS7, Diameter, and/or SIP in telecom environment
• Experience in roaming/fra...