{HEAD ~ The buffer} receives {TAIL ~ a data frame} to be transmitted to a destination device via the switching fabric 
{ HEAD ~ The buffer } receives { TAIL ~ a data frame } to be transmitted to a destination device via the switching fabric
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH