The source address of the first packet is set to the first address when {HEAD ~ the first packet} is related to the first service and to the second address when {TAIL ~ the first packet} is related to the second service 
The source address of the first packet is set to the first address when { HEAD ~ the first packet } is related to the first service and to the second address when { TAIL ~ the first packet } is related to the second service
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH