At debian using aria2 to download with multiple simultaneous connections
apt-get install -y aria2
Download with 16 simultaneous connections:
time aria2c -x 16 -i downloadfile.txt
Status Legend:
(OK):download completed.
real 2m33.657s
user 0m3.644s
sys 0m5.772s
Much quicker than 20mins.
tar -cvzf openwrtyun.tar.gz openwrtyun
Upload openwrtyun.tar.gz into https://www.dropbox.com