The non-limiting embodiments of the present technology relate to the data transmission technology in packet-switched Software Defined Networks (SDN), comprising switches with Ethernet ports and controlled by software controllers. The aim of this technical solution is to increase network switches' resource efficiency by establishing frame transport path in the network with MPLS transport tags set by the network controller as well as to reduce software functional requirements for OpenFlow switches and controllers by supporting standard frame fields processing. Method for forming an Ethernet frame and methods for transferring the Ethernet frame are disclosed.