A cache device may be configured to disallow the transmission of expired content, and to contact the streaming server 100 in {HEAD ~ order} to receive {TAIL ~ updated content} 
A cache device may be configured to disallow the transmission of expired content , and to contact the streaming server 100 in { HEAD ~ order } to receive { TAIL ~ updated content }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL