A method performed by a policy node for handling QoS for data traffic between a UE and an Application Server (AS) node associated with the UE. The policy node receives messages indicating available marking types which a user plane node is capable of detecting in the data traffic and information indicating a number of marking types supported by both the UE and the AS node, a UE identifier identifying the UE and a list of QoS profiles associated with the UE. The policy node determines the decided marking type and marking value for each of the QoS profiles associated with the UE identifier and transmits a message towards the control plane node having a session establishment response for the UE identifier including the marking type and marking value decided for each QoS profile associated with the UE identifier.