The present disclosure relates to a method, performed in a single IP-address source node in a wireless communication network, of establishing a multipath TCP, MPTCP, connection for transfer of TCP data in MPTCP subflows to a destination node. The single IP-address source node receives an MPTCP trigger to activate a multipath TCP connection. One or more source TCP ports are selected, wherein each source TCP port is selected to constitute a starting point of an MPTCP subflow. One or more MPTCP notifications are sent to the destination node. Each MPTCP notification includes information on a selected source TCP port. The single IP-address source node receives an acknowledgment of each MPTCP notification from the destination node.