Here are some links to help speed your server or network up for better hosted backup results. Be careful to always back up your computers before tweeking! Write everything down so you can reverse settings if you get problems.
Speak with your ISP if you find your network to still be slow after trying some tweeks. Most ISP's have several different account speed options at different price levels.
Broadband Speed & TCP Settings, Tweeks and Network Vulnerabilites
File Transfer Speed Calculator & analysis