sending an initial request from {HEAD ~ the device} to {TAIL ~ the first ingress router} prior to migrating to the second routing domain, the request to buffer the received packets in advance of migrating 
sending an initial request from { HEAD ~ the device } to { TAIL ~ the first ingress router } prior to migrating to the second routing domain , the request to buffer the received packets in advance of migrating
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH