In general, {HEAD ~ techniques} are described for hierarchical application of security services with {TAIL ~ a network device} 
In general , { HEAD ~ techniques } are described for hierarchical application of security services with { TAIL ~ a network device }
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL