MNP (Mobile Number Portability)

Mobile Number Portability lets subscribers change operator while keeping their MSISDN, mandated by regulators in most markets. It is implemented through a national number portability database that operators query during call/SMS routing. MNP processes are also a frequent attack surface for SIM-swap-style social engineering, where an attacker ports the victim's number to an operator they control.

Categories: Identity and SubscriberSecurity ControlsThreats and Attacks

MNP in context

Subscriber identifiers (IMSI, SUPI, MSISDN, IMEI) anchor authentication, charging and lawful interception. Any protocol that leaks a permanent identifier is treated as a privacy defect, which is why 5G introduced SUCI concealment on the air interface.

Security controls span signaling firewalls (SS7/Diameter/GTP screening), transport encryption (IPsec, TLS, PRINS), identity and access on OSS/BSS, and monitoring at both packet and log level. Controls are audited against GSMA FS.11/FS.19/FS.20/FS.36.

To place MNP in the wider telecom-security picture, review CLI Spoofing, IMEI, RPKI, STIR, SIM Swap and Port-Out Fraud: each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

Related topic hubs

  • Diameter Attacks S6a IDR/PUR/CLR abuse, subscriber tracking, LTE signaling attacks.
  • SMS Firewall SMS spam, phishing, A2P bypass and MAP-layer SMS filtering.
  • Signaling Firewall Unified SS7/Diameter/GTP/SMS signaling firewall framework.
  • Silent SMS Type-0 SMS location tracking and detection.

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.