Are you able to browse by IP? Try putting http://22.214.171.124/
into your browser, and see if you can connect.
If so, you're connected, but aren't looking up any names. You need to find the IP addresses of your ISP's nameserver(they should have given them to you with the username and password) and add them to /etc/resolv.conf (you'll need to be root). Dial up again and try that.