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