Intelligent Network

The Intelligent Network was an ITU-T architecture (CS-1, CS-2) developed in the 1990s to decouple service logic from switches, allowing operators to deploy services such as freephone, VPN, and prepaid through a Service Control Point that the MSC consulted via the INAP signalling protocol. Largely superseded by IMS and CAMEL/CAP, IN logic still runs in many legacy networks and remains a fraud surface.

Categories: Core NetworkSignalingFraud

IN in context

The mobile core is where subscriber sessions, mobility and policy live. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF. Core exposure is the difference between a single-subscriber leak and a fleet-wide breach.

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.

To place IN in the wider telecom-security picture, review 5G SBA, IAMF, SMS, GSMA Open Gateway, GTP and HSS.

Related terms

Related topic hubs

  • SS7 Security SS7/MAP/CAP/SCCP attacks and defenses across 2G/3G interconnect.
  • Diameter Security 4G/LTE Diameter threats across IPX/roaming and DEA defenses.
  • Diameter Attacks S6a IDR/PUR/CLR abuse, subscriber tracking, LTE signaling attacks.
  • Signaling Firewall Unified SS7/Diameter/GTP/SMS signaling firewall framework.

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.