The switch device is arranged to route {HEAD ~ paths} between {TAIL ~ the second interface} and the first interface 
The switch device is arranged to route { HEAD ~ paths } between { TAIL ~ the second interface } and the first interface
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH