What is The M-Plane in Open RAN?
January 31, 2023

First, to understand the function of the fronthaul M-Plane, let’s remember the Fronthaul Planes, Please read this and continue. 

What are C/U/M/S Fronthaul (FH) Planes in ORAN ?

What is the M-Plane? 

Management Plane: refers to non-real-time management operations between the O-DU and the O-RU like: 

  • Performance Management (PM).
  • Configuration Management (CM).
  • Fault Management (FM).
  • File Management.

What are the M-Plane Archtecture?

The M-Plane supports two architectural models for O-RU Management:

  • Hierarchical management model
    • The O-RU is managed entirely by one or more O-DU(s) using a NETCONF-based M-Plane interface. When the O-RU is managed by multiple O-DUs, it is typically for enabling O-DU and/or transport connectivity redundancy capabilities.
  • Hybrid Management model
    • The hybrid architecture enables one or more direct logical interfaces between management systems and O-RU in addition to a logical interface between O-DU and the O-RU ( Which is called here Open Fronthaul M-Plane).
    • It should be noted that the NETCONF clients connecting to the O-RU may be of different classes (e.g. O-DU and NMS). For example, functions like O-RU software management, performance management, configuration management, and fault management can be managed directly by the management system(s).
    • The O-RU has end-to-end IP layer connectivity with the NMS. From a physical network point of view, this connectivity could be via the O-DU, where the O-DU is acting as an IP/Ethernet packet forwarder, and forwards the packets between O-RU and the NMS.
    • Direct logical communication between an O-RU and NMS can be enabled via O-RUs being assigned routable IPs or local private IPs resolved by a NAT function in the network (or implemented at the O-DU).
    • Configuration of “non-carrier” aspects of an O-RU together with functions like O-RU software management, file management, trace, and troubleshooting are managed directly by the management system (e.g., SMO).
    • For carrier-related parts, management is performed by the OAM function of the O- DU, based on SMO-provided configuration information via the O1.


  • There is no explicit signaling to indicate that an O-RU is operating in a hierarchical or hybrid configuration. All NETCONF servers supporting this M-Plane specification shall support multiple NETCONF sessions, and hence all complaint O-RUs shall be able to support both hierarchical and hybrid deployment.
  • NETCONF server exists in O-RU.
  • NETCONF Client exists in O-RU Controller which can be O-DU or NMS. 
  • NETCONF also natively supports a hybrid architecture that enables multiple clients to subscribe and receive information originating at the NETCONF server in the O-RU.


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