About
Youssef Elouam
Telecom & Core Network Expert
Doha, Qatar
I am a telecom and core network engineer with over fifteen years of experience across mobile core, signalling infrastructure and messaging platforms. My work focuses on four interconnected domains: SS7, Diameter and SIP security; signalling routing (STP/DRA); IMS/VoLTE/VoNR architecture; and messaging services including RCS and XMS platforms.
On the security side, I specialise in identifying and mitigating vulnerabilities in SS7, Diameter and SIP signalling stacks — the protocols that underpin subscriber authentication, roaming, call control and messaging across virtually every mobile network on the planet. I conduct signalling security assessments, design firewall and filtering rules, and advise on GSMA security hardening guidelines (FS.11, FS.19, FS.21).
In parallel, I work on IMS core deployments — the infrastructure behind VoLTE and VoNR voice services — and on messaging platform architecture covering SMS, RCS and A2P/P2A services. I write here about what I encounter in that work: protocol deep-dives, security analysis, and the gaps between what standards specify and what implementations actually do.
Technical expertise
SS7 / Diameter / SIP Security
- SS7 vulnerability assessment
- Diameter security hardening
- SIP TLS / SRTP
- Signalling firewall design
- IPX interconnect security
- GSMA FS.11 / FS.19 / FS.21
Signalling Routing (STP / DRA)
- Signal Transfer Point (STP)
- Diameter Routing Agent (DRA)
- SCCP / ISUP routing
- Diameter routing tables
- Roaming & interconnect
- Load balancing & failover
IMS / VoLTE / VoNR
- IMS core architecture
- P/S/I-CSCF, HSS, PCRF
- VoLTE / VoNR call flows
- SIP registrar & proxy
- Emergency services (IMS-E)
- QoS & bearer management
XMS & Messaging (RCS)
- RCS / GSMA UP 2.x
- SMS / MMS / SMPP
- SMSC / MMSC
- A2P / P2A messaging
- Messaging hub architecture
- OTT & CPaaS integration
Education
Engineering Degree
Telecommunications & Computer Science
École Mohammadia d'Ingénieurs (EMI)
Certifications
VMware Certified Professional — Data Center Virtualization
VMware
ITIL® Foundation Certificate in IT Service Management
AXELOS
How I approach this work
Protocol-first
I read the RFCs and 3GPP specs before touching a trace. Most signalling problems — and most security gaps — come from the distance between what the standard says and what the implementation does.
Attacker perspective
The most effective way to harden a signalling network is to think through how it can be abused. I approach SS7, Diameter and SIP security by modelling the attack first, then designing the countermeasure.
Clarity over jargon
Telecom is dense with acronyms. I write and communicate so that technically sharp people outside the industry can follow the reasoning — not just fellow telco engineers.