Among the factors considered in the optimization are {TAIL ~ the characteristics} of the originating source and {HEAD ~ the network path} 
Among the factors considered in the optimization are { TAIL ~ the characteristics } of the originating source and { HEAD ~ the network path }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD