{TAIL ~ Instead, notification mechanisms} within {HEAD ~ the workstation 114 confirm successful reception}, at a receiving port , of a test request issued from a transmitting port  
{ TAIL ~ Instead , notification mechanisms } within { HEAD ~ the workstation 114 confirm successful reception } , at a receiving port , of a test request issued from a transmitting port
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH