After the routing data is added to the data frame, {TAIL ~ the buffer} transmits {HEAD ~ the data frame} to the switching system 
After the routing data is added to the data frame , { TAIL ~ the buffer } transmits { HEAD ~ the data frame } to the switching system
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH