In the GwebCache , if a client request the other serveral cache,this GwebCache will respond with the url, but when client want to request host , it will get the remote node ip and port ,why ?can't we implment the other cache with the ip and port?

i know most node have the dynamic ip , like me , so we must bind the url to ip , and use this ip as our sign.but why does implement the other host with the url ??