{TAIL ~ The switching fabric} comprises a plurality of data ports through which {HEAD ~ data frames} enter or exit the switching fabric 
{ TAIL ~ The switching fabric } comprises a plurality of data ports through which { HEAD ~ data frames } enter or exit the switching fabric
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH