Open Fronthaul (O-RAN 7-2x Fronthaul Interface)

Also known as: OFH, 7-2x Fronthaul

The Open Fronthaul is the O-RAN Alliance's standardised interface between O-DU and O-RU at the 7-2x functional split. It defines four planes: CUS-Plane (control, user, synchronisation) over eCPRI, M-Plane for management over NETCONF/YANG, and S-Plane for time sync via PTP/SyncE. Because Open Fronthaul is a multi-vendor and often physically exposed link, WG4 mandates 802.1X, MACsec/IPsec and PTP authentication to prevent interception and time-sync attacks.

Categories: Radio Access NetworkProtocols and Standards

Open Fronthaul 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.

Telecom security is written into standards from 3GPP, GSMA, ETSI, IETF and ITU-T. Understanding which body owns which specification, and how they interlock, is essential for both design and audit work.

To place Open Fronthaul in the wider telecom-security picture, review 5GNR, 6G, ADSL, DOCSIS, EAP and ETSI — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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