a control unit that is designed to convert an Ethernet telegram received via {HEAD ~ the first interface} into an internal data telegram and to output {TAIL ~ the internal data telegram} via the second interface 
a control unit that is designed to convert an Ethernet telegram received via { HEAD ~ the first interface } into an internal data telegram and to output { TAIL ~ the internal data telegram } via the second interface
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH