A method of configuring optical network nodes (6a, 6b) between a plurality of Remote Radio Units (4a, 4b) and at least one Baseband Unit (2a, 2b). The method comprises monitoring a bandwidth demand of each Remote Radio Unit (4a, 4b), and calculating a routing configuration of the nodes to connect at least one Remote Radio Unit on a tree arrangement to a said Baseband Unit. The calculating (82) the routing configuration is based on at least one connection requirement between the Remote Radio Units and the Baseband Units and the bandwidth demand of each Remote Radio Unit. The method further comprises dynamically configuring one or more optical network nodes to adapt the routing configuration from a said Remote Radio Unit to a said Baseband Unit, according to the calculated routing configuration.