As outlined in the Knowledge Base section discussing the DU, there are two main components to the DU: the DU-high and DU-low.

The srsRAN Project DU follows the architecture seen in the Knowledge Base, with the addition of the DU Manager. This results in the DU having the following architecture:

DU Architecture

From this we can clearly see how the DU is split into the DU-high and DU-low, with the following main components and interfaces:


  • DU Manager: This is an srsRAN Project specific component and implementation

  • F1AP-DU: The DU specific implementation of the F1AP

  • RLC: Radio Link Control

  • MAC: Medium Access Control


  • E2: Interfaces with the nRT RIC

  • F1-c: Interfaces with the CU control plane

  • F1-u: Interfaces with the CU user plane

  • FAPI: Interface between the DU-high and DU-low


These are discussed in detail in the Interfaces section


Documentation discussing the implementation of the DU-low and its components can be found here.