When your Internet connection breaks down, it's not possible to use that connection to consult technical support websites or send email to your network provider. Therefore, it's often helpful to have a backup method for connecting at least one of your computers to the Internet. It might be a neighbor's Wi-Fi network (with their permission, of course), a nearby library or coffee shop that offers Internet access, or a link through a dial-up telephone line and modem.
Before you have a problem, ask your Internet service provider if they offer dial-up access along with their high-speed services. If they do, ask them for a dial-up account as an emergency backup, and make a note of the access telephone numbers, login name, and password in your network notebook.