There simply are not enough telephone lines to support all potential Internet users should they all decide to dialup at the same time.  ISPs attempt to manage the number of available lines to handle peak traffic as best they can but sometimes the number of users trying to use the same number will exceed the available capacity.  If this happens, there are three things you can do.

Check for an Alternate Number. Check for alternate numbers that are local to you by selecting the ACCESS NUMBERS button to the left or Click Here. Please check with your local telephone operator to ensure that any alternate number you might choose is local to you.  (Review the information at the bottom of the Access Numbers page).

Check With Your Local Phone Company. When you connect to the Internet, your first stop is your local phone company.  It is possible that they are experiencing a problem. You can contact them and have them check their lines for a problem.

Contact Your ISP. Your ISP makes use of national carrier networks, and the problem might be there.  Contact your ISPs Technical Support and report the problem.