said {HEAD ~ sub step} in step further comprises determining {TAIL ~ the survivability characteristics} of the modified network topology; and 
comprises determining
said { HEAD ~ sub step } in step further comprises determining { TAIL ~ the survivability characteristics } of the modified network topology ; and
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH