Embodiments herein relate to a method performed by a RAN node (12), for managing communication on a first network slice in a communications network (1). The communications network (1) comprises partitioned sets of functionalities. A first set of functionalities belongs to the first network slice. The first set of functionalities is at least 5 partly separated from another set of functionalities out of a total set of functionalities in the communications network (1). The RAN node (12) receives, from a CN node (16), information regarding requested resources for a first network slice identified by a network slice identifier. The RAN node (12) determines that the received information does not correspond to a Service Level Agreement (SLA) for the first network slice.