Understanding browser timelines

I have a ColdFusion server (running on localhost) and I am trying to optimize my application. My question is about information in the browser timeline (FF and Chrome return the same values).

I have a cfm test page that only returns 100 bytes of static data. When debugging the CF, it says the execution time is 3ms. However, the browser timing says the browser waits for about 1.2 seconds. I ran Fiddler and it also reported similar times for server side processing.

These discrepancies also happen (only worse) when I test pages that actually work. for example the difference between onrequeststart and onrequestend is 400ms, but the browser timeout is 2.2s.

So this is just "overhead", there is nothing I can do or anything I can do to reduce the "latency"?