{HEAD ~ Connection} and {TAIL ~ disconnection} to and from the hosts are carried out according to the host information 
{ HEAD ~ Connection } and { TAIL ~ disconnection } to and from the hosts are carried out according to the host information
HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH