How to download via home-brew when connected though Internet dongle?

I wanted to download python on my Mac OS Mavericks. I found a blog which instructed to download it via home-brew using simple command

brew install python

But I am getting failed to download errors. I am connected to the internet via my 3G dongle but when I type into the terminal

curl http://www.google.com

Nothing happens!! Could it be the case that I am unable to access internet via the terminal when connected through a dongle? If so please suggest how do I make this to work!!