The present invention relates to providing a generic control plane in a GTP mobility protocol in a core network. When a type of user plane is detected, a user plane parameter is provided in a control plane message header. The user plane message indicates the type of user plane. Functions, parameters and messages are provided according to the indicated type of user plane. Thus, e.g. easier hand over between different access networks can be provided and an optimization of the user plane implementation in an edge node.