I just installed apt cacher ng for catching my apt upgrade packages and saw a huge time improvement even though I have a good internet connection. It act as a proxy and caches the response packages.
Do you run something similar? Or maybe even run a local repo mirror? Warning, they are really big so I don't think it is recommended unless you really need almost everything.
Do you know you can use the ISO files as repositories? Easier in some situations.
sudo mkdir -p /media/repo_1 sudo mkdir -p /media/repo_2 sudo mkdir -p /media/repo_3
/etc/apt/sources.list
file to add the repositoryvim /etc/apt/sources.list deb file:///media/repo_1/ jessie main contrib deb file:///media/repo_2/ jessie main contrib deb file:///media/repo_3/ jessie main contrib
sudo apt-get update