Patent ID: 8923303

Claim:
A data transmission installation for forwarding data transmission frames, the data transmission installation comprising data receivers for receiving data transmission frames in the data transmission installation, data transmitters for sending data transmission frames from the data transmission installation, first and second output ports for connecting the data transmission installation to be a part of ring-shaped data transmission topology, and a processor unit adapted to: read control data from one or more received data transmission frames, the control data containing building and cancelling commands for logical data transmission tunnels determined on the basis of mobility of data terminals connected to a data transmission network, execute building and cancelling actions determined by the control data for logical data transmission tunnels, and determine forwarding actions for a received second data transmission frame on the basis of forwarding control data contained in the second data transmission frame, the forwarding actions being selected on the basis of the forwarding control data from a set comprising the following forwarding actions (i-iii): (i) a transmission of the second data transmission frame by way of the first output port, (ii) a transmission of the second data transmission frame by way of one of the first and second output ports, and (iii) a transmission of the second data transmission frame by way of a logical data transmission tunnel commencing from the data transmission installation.