A network switch according to claim 1 wherein said at least one data port interface is configured to receive data which includes a packet having headers, said portion of said data comprises {HEAD ~ a parsed field} derived from {TAIL ~ said headers.1} 
A network switch according to claim 1 wherein said at least one data port interface is configured to receive data which includes a packet having headers , said portion of said data comprises { HEAD ~ a parsed field } derived from { TAIL ~ said headers.1 }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL