A method performed by a core network node for obtaining a decision of a Core Network, CN,/Radio Access Network, RAN, endpoint pair for a user plane session between a RAN, and a CN in a radio communications network , the RAN comprises multiple RAN transport endpoints, RAN endpoints, , and the CN comprises multiple CN transport endpoints, CN endpoints, , the method comprising: obtaining identifiers of available CN endpoints in the CN , and obtaining identifiers of available RAN endpoints in the RAN , which available CN endpoints and available RAN endpoints comprises a number of possible transport endpoint pairs between the RAN and the CN , CN/RAN endpoint pairs, obtaining characteristics of a respective transport path of the number of possible CN/RAN endpoint pairs, obtaining a decision of a CN/RAN endpoint pair out of the number of possible CN/RAN endpoint pairs, based on the obtained characteristics of the respective transport path of the number of possible CN/RAN endpoint pairs, which CN/RAN endpoint pair is selected for the user plane session between the RAN and the CN in the radio communications network , Z wherein the method is characterised by the core network node further obtaining the decision of the CN/RAN endpoint pair by basing it on a negotiation with the RAN comprising to: send a request associated with the user plane session to a RAN node comprising the RAN endpoints , which request is adapted to comprise either the identifiers to all available CN endpoints or one or more identifiers to a recommended CN endpoint, for the user plane session between the RAN and the CN , and receive from the RAN node , a response to the sent request, which response is adapted to comprise identifiers of one or more recommended CN/RAN endpoint pairs based on the identifiers to all available CN endpoints or the recommended CN endpoint/endpoints in the sent request. obtaining identifiers of available CN endpoints in the CN , and obtaining identifiers of available RAN endpoints in the RAN , which available CN endpoints and available RAN endpoints comprises a number of possible transport endpoint pairs between the RAN and the CN , CN/RAN endpoint pairs, obtaining characteristics of a respective transport path of the number of possible CN/RAN endpoint pairs, obtaining a decision of a CN/RAN endpoint pair out of the number of possible CN/RAN endpoint pairs, based on the obtained characteristics of the respective transport path of the number of possible CN/RAN endpoint pairs, which CN/RAN endpoint pair is selected for the user plane session between the RAN and the CN in the radio communications network , Z wherein the method is characterised by the core network node further obtaining the decision of the CN/RAN endpoint pair by basing it on a negotiation with the RAN comprising to: send a request associated with the user plane session to a RAN node comprising the RAN endpoints , which request is adapted to comprise either the identifiers to all available CN endpoints or one or more identifiers to a recommended CN endpoint, for the user plane session between the RAN and the CN , and receive from the RAN node , a response to the sent request, which response is adapted to comprise identifiers of one or more recommended CN/RAN endpoint pairs based on the identifiers to all available CN endpoints or the recommended CN endpoint/endpoints in the sent request. send a request associated with the user plane session to a RAN node comprising the RAN endpoints , which request is adapted to comprise either the identifiers to all available CN endpoints or one or more identifiers to a recommended CN endpoint, for the user plane session between the RAN and the CN , and receive from the RAN node , a response to the sent request, which response is adapted to comprise identifiers of one or more recommended CN/RAN endpoint pairs based on the identifiers to all available CN endpoints or the recommended CN endpoint/endpoints in the sent request. <EOS>