Dial-Up Networking

• Dial-up networking requires a dial-up device on your system (e.g. an analog modem, or an ISDN card).
  
  
• A modem is a device that allows one to make data calls over a regular phone line. A modem sounds like "tzrrrrr....brrrr....grrr....".
  
  
• Most modems sold today work at speeds of 33,600 bps (bit per second), or 57,600 bps.
  
  
• Modems are normally controlled by textual commands, called "AT commands". All these commands begin with the letters "AT". A few examples:
  • ATZ - reset the modem to its stored default settings.
  • ATDT8319000 - dial, using tone dial, to the given phone number.
  • ATL3 - set the volume of the modem's speaker to level 3 (maximum).
  
  
  
• Linux supports modems that support themselves - i.e. modems that contain all the hardware required for their working. This includes all external modems, and many internal modems.
  
  
• There are modems, called 'winmodems' or 'HSP modems', that rely on the computer's CPU to perform part (or all) of their signal processing operations. These modems often are supplied with windows-only drivers, and are generally not supported by Linux.
  
  
• However, some companies regained consciousness lately, and started delivering Linux drivers as well. For more info, look at http://www.linmodems.org/.
  
  
• As for ISDN controllers, there are quite a few supported by Linux, including many which are provided by Israeli ISPs.
  
  
• Finally, there are also various cellular "modems", that may be used to connect a PC (usually a notebook) to the Internet using a cellular phone line. Some of them are not supported by Linux, but some work properly.