A method, performed by a RAN node, for enabling connection setup for a wireless device in a communication network comprising a first network which is a home network of the wireless device and a second network which is visited by the wireless device. The networks each comprise partitioned sets of functionalities, which sets of functionalities each belong to a network slice of the network, wherein a first set of functionalities in the first network belongs to a first network slice supporting the wireless device. The RAN node receives a first network identity for the home network, an identity of the first network slice supporting the wireless device in the home network and a second network identity for the second network, from the wireless device, to retrieve an identity of a second network slice capable of supporting the wireless device in the second network to determine a second core network node.