Xn Interface

In telecommunications, Xn is the 3GPP-defined interface between two gNBs (or between a gNB and an ng-eNB) used for handover signaling, dual connectivity, and load management. Xn-C carries control plane and Xn-U carries user plane, both protected with IPsec.

Categories: Radio Access NetworkSignalingSecurity Controls

Xn Interface in context

The radio access network is where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations and downgrade attacks; defenses rest on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

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 Xn Interface in the wider telecom-security picture, review 1G, ITU, Lawful Interception, RADIUS, RTP and SIP — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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