E.164

E.164 in context

Signaling protocols carry the control-plane instructions that set up calls, register subscribers, hand over sessions and route SMS. SS7, Diameter, GTP-C and SIP are the four dominant families, and interconnect exposure of any of them is treated by GSMA FS.11 / FS.19 / FS.20 as a top-tier telecom risk.

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

To place E.164 in the wider telecom-security picture, review OCS, Number Portability, IMSI, MSC, P-Asserted-Identity and ENUM.

Related terms

• OCS
• Number Portability
• IMSI
• MSC
• P-Asserted-Identity
• ENUM
• MCC
• X.509

Related topic hubs

• Signaling Firewall Unified SS7/Diameter/GTP/SMS signaling firewall framework.
• SS7 Security SS7/MAP/CAP/SCCP attacks and defenses across 2G/3G interconnect.
• SS7 Firewall GSMA FS.11 category 1/2/3 SS7 message screening at the STP edge.
• SS7 Penetration Testing Interconnect pentest methodology for SS7 signaling.

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.