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