A method of supporting Adaptive Bit Rate, ABR, video resolution shaping of a video data stream of a video session transferred by a User Plane Function, UPF, in a Service Based Architecture, SBA, domain deployed in a telecommunications system, wherein said UPF is a network node, said method comprising the steps of: - determining, by said UPF, a video resolution of a video data stream received by said UPF; - establishing, by said UPF, based on said determined video resolution and a required video resolution of said video session, a video resolution shaping level to be applied at said received video data stream for achieving said required video resolution of said video session, wherein said video resolution shaping level comprises a bit rate of said video data stream to be transferred by said UPF; - applying, by said UPF, said video resolution shaping on said received video data stream; and - transferring, by said UPF, said received video data stream at which said video resolution shaping is applied; the method being characterized by: said step of establishing said video resolution shaping is being performed by said UPF implementing a Reinforcement Learning Agent, RLA, operating with an observation space composed of possible video resolution states comprising said determined video resolution, and an action space comprising video resolution shaping levels to be applied at said received video data stream; wherein said video resolution of said received video data stream is computed, by said UPF, for a video chunk of said received video data stream and wherein the UPF computes a video resolution state of said video chunk based on said video resolution and computes an associated reward based on said computed video resolution state, on said required video resolution and on an overall network load; wherein said action space is configured based on a Maximum Bit Rate, MBR, and on said required video resolution; wherein said RLA selects the video resolution shaping to be applied from said action space based on said video resolution state, said associated reward and a level of operation of the RLA; wherein the level of operation of the RLA comprises the policies learned by the RLA to map the possible video resolution states to video resolution shaping levels within the action space, whether the RLA is in exploration or exploitation mode, and a size of the action space; and wherein the required video resolution and the MBR are provided by a Policy Control Function, PCF, as part of Policy and Charging Control, PCC, rules when a user establishes a Protocol Data Unit, PDU, session. - determining, by said UPF, a video resolution of a video data stream received by said UPF; - establishing, by said UPF, based on said determined video resolution and a required video resolution of said video session, a video resolution shaping level to be applied at said received video data stream for achieving said required video resolution of said video session, wherein said video resolution shaping level comprises a bit rate of said video data stream to be transferred by said UPF; - applying, by said UPF, said video resolution shaping on said received video data stream; and - transferring, by said UPF, said received video data stream at which said video resolution shaping is applied; said step of establishing said video resolution shaping is being performed by said UPF implementing a Reinforcement Learning Agent, RLA, operating with an observation space composed of possible video resolution states comprising said determined video resolution, and an action space comprising video resolution shaping levels to be applied at said received video data stream; wherein said video resolution of said received video data stream is computed, by said UPF, for a video chunk of said received video data stream and wherein the UPF computes a video resolution state of said video chunk based on said video resolution and computes an associated reward based on said computed video resolution state, on said required video resolution and on an overall network load; wherein said action space is configured based on a Maximum Bit Rate, MBR, and on said required video resolution; wherein said RLA selects the video resolution shaping to be applied from said action space based on said video resolution state, said associated reward and a level of operation of the RLA; wherein the level of operation of the RLA comprises the policies learned by the RLA to map the possible video resolution states to video resolution shaping levels within the action space, whether the RLA is in exploration or exploitation mode, and a size of the action space; and wherein the required video resolution and the MBR are provided by a Policy Control Function, PCF, as part of Policy and Charging Control, PCC, rules when a user establishes a Protocol Data Unit, PDU, session.