: Stopping port scans and SIP fingerprinting used to map network vulnerabilities. Routing Attack Mitigation
It introduces the concept of comparing fields across different protocols (e.g., SIP vs. Diameter) to identify discrepancies that signal potential fraud or security breaches. Integration with Other GSMA Standards
: FS.38 is frequently used as a baseline for Telecom Security Assessments to evaluate if Voice over LTE (VoLTE) or Hosted Voice deployments are vulnerable. Why It Matters Interworking Security - GSMA
Before GSMA FS.38, SIM profiles were largely proprietary. A profile built by one vendor might only work on chips from that same vendor. FS.38 changed this by defining a generic, neutral format for how a SIM profile is described, packaged, and loaded onto an eUICC (embedded Universal Integrated Circuit Card).
At the device layer, FS.38 mandates fundamental controls such as secure boot, encrypted storage for credentials, and the principle of least functionality (disabling unnecessary ports and services). The guideline specifically emphasizes the protection of the or eSIM (eUICC) , treating the Subscriber Identity Module (SIM) as the root of trust for network authentication.
: Testing must include SIP endpoints, SBCs (which act as "SIP firewalls"), and even non-SIP nodes like provisioning servers.