Defense in Depth

In telecom networks, Defense in Depth is the layering of independent security controls so that no single failure exposes the network. Typical telecom layers include perimeter signaling firewalls, MAP/Diameter/GTP screening, SEPP at the 5G interconnect, intra-core segmentation, NF-to-NF authentication, OAM bastioning, and detection through a telecom SIEM.

Categories: Core NetworkSignalingRoaming and Interconnect

Defense in Depth in context

The mobile core carries subscriber sessions, mobility and policy. 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.

Signaling protocols carry the control-plane messages that set up calls, register subscribers 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 as top-tier telecom risk.

To place Defense in Depth in the wider telecom-security picture, review FS.07, FS.19, GGSN, GTP, GTP Firewall and HLR — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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.