Slow load time - 16 seconds

Hello,

My site is taking a long time to load and i cant figure out what the problem is. From the waterfall view in the results it shows that the content download (blue bar) is the problem. How can i fix this? any idea?

This page is the landing page which links to a number of subdomains. They two are loading at the same speed. 16-20 Seconds

Test results
http://www.webpagetest.org/result/111112_5A_25HJA/1/details/

Donal