This disclosure relates to supporting handling of state information for a stateful network function of a communication network. The network function of the communication network is provided by a network function environment including a set of network function instances configured to provide the network function, a scheduler configured to receive messages of subscribers of the communication network and to distribute the messages to the network function instances for processing by the network functions instances in accordance with the network function, and a state information storage device configured to store state information of the subscribers. The network function instances are configured to temporarily store state information of the subscribers locally at the network function instances while subscribers are associated with the network function instances and to transfer state information of the subscribers to the state information storage device when the subscribers are no longer associated with the network function instances.