{HEAD ~ The combination} of {TAIL ~ the FEC value} 515, the data block 500A, the FEC value 515′ and the data block 500A′ is the adaptive response 505A by the retransmit server 110A to the repair server 120A 
of
{ HEAD ~ The combination } of { TAIL ~ the FEC value } 515 , the data block 500A , the FEC value 515′ and the data block 500A′ is the adaptive response 505A by the retransmit server 110A to the repair server 120A
HEAD HEAD HEAD HEAD HEAD HEAD REL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH