A Network Node, a Radio Access node and methods therein for handling and supporting Hand Over, HO, in a wireless communication network are disclosed. The method in a Radio Access node comprises receiving, from a Network Node, a VoIP session notification identifying a traffic flow associated with VoIP related to a UE. The method further comprises receiving, from the Network Node, a VoIP state report for the identified traffic flow, said VoIP state report comprising a determined VoIP state, and a prediction related to a time to a VoIP state change. Further, the method comprises, when the UE is a candidate for HO: deciding whether to delay or to trigger the HO based on the VoIP state and the prediction.