What is meaning of 'Blocking' in Firebug Net Panel?

Question

I\'m using Firebug 1.5.2 and while testing a site before production release i can see a huge amount of time consumed by \'Blocking\' parts of the requests.

What exa

Answer 1

"Blocking" previously (earlier versions of FireBug) was called "Queuing". It actually means that request is sitting in queue waiting for available connection. As far as I know number of persistent connections by default is limited in last versions of Firefox to 6, IE8 also 6. Earlier it was only 2. It can be changed by user in browser settings.
Also as I know that while javascript file is loading, all other resources (css, images) are blocked