GTP-C (GTP Control Plane)

Also known as: GTP Control Plane, GTPv2-C

GTP-C is the control-plane variant of the GPRS Tunnelling Protocol used to create, modify and delete PDP contexts and PDN/PDU sessions between core nodes (S5/S8, S11, S16, N26). GTPv1-C serves 2G/3G/legacy roaming and GTPv2-C serves EPC and 5G interworking. Manipulation of GTP-C is a documented roaming attack surface: session hijack, DoS, subscriber tracking and forced downgrade, which is why GTP firewalls inspect it in addition to GTP-U.

Categories: Core NetworkSignalingRoaming and Interconnect

GTP-C 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 GTP-C 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

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