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