O1 Interface (O-RAN Management Interface)

Also known as: O1

The O1 interface is the O-RAN management-plane interface from the SMO to O-RAN managed functions (O-CU, O-DU, O-RU, Near-RT RIC). It carries FCAPS operations (fault, configuration, accounting, performance, security) using NETCONF/YANG and file-transfer protocols. O1 is a high-value target: compromise gives an attacker configuration control over the entire RAN.

Categories: Radio Access NetworkSignalingOperations and Business

O1 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 O1 Interface in the wider telecom-security picture, review 1G, 5G SA, AMF, Base Station (BS), Billing System and BSS — 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.