The route information of each link of {HEAD ~ the plurality} of links is updated in {TAIL ~ real time} 
The route information of each link of { HEAD ~ the plurality } of links is updated in { TAIL ~ real time }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL