X3 (LI) (Lawful Interception X3 Interface — Content of Communication)
Also known as: LI X3, X3 LI interface
Categories: Threats and AttacksProtocols and StandardsRegulation and Compliance
X3 (LI) in context
Telecom threats range from opportunistic SMS phishing and SIM swap to nation-state grade location tracking and lawful-interception abuse. The common thread is that most attacks exploit the inherited trust model of legacy signaling. SS7 and Diameter were designed for a closed operator community that no longer exists.
Telecom security is written into standards from 3GPP, GSMA, ETSI, IETF and ITU-T. Understanding which body owns which specification, and how the specs interlock (for example 3GPP TS 33.501 with GSMA FS.34 for 5G SBA security), is essential for both design and audit work.
To place X3 (LI) in the wider telecom-security picture, review X2 (LI), ETSI TS 103 221, X1, IRI, CC (LI) and HI2.
Related terms
Equipment
Lawful interception systems (ADMF, mediation, HI1/2/3)
Related topic hubs
- Diameter Attacks S6a IDR/PUR/CLR abuse, subscriber tracking, LTE signaling attacks.
- VoLTE Security IMS/VoLTE signaling risk: SIP, IMS-AKA, media plane attacks.
- IMS Security Training Training on IMS, VoLTE/VoNR, SIP and RCS security.
- Diameter Security 4G/LTE Diameter threats across IPX/roaming and DEA defenses.
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.