This occurs when you have set up your computer to connect automatically when a TCP/IP application needs to access the Internet. Certain applications or services, such as Web Sharing (Apache), Windows Sharing, and the Directory Access SMB Plug-in, may look for a TCP/IP connection, causing your modem to dial. To avoid this, use Network preferences to change your PPP or PPPoE Options:
For a PPP connection
- Open System Preferences.
- Click Network.
- From the Show menu ("Configure" menu prior to Mac OS X 10.1), choose Internal Modem.
- Click the PPP tab, then PPP Options.
- Deselect the checkbox for "Connect automatically when needed" (or in earlier Mac OS X versions, "Connect automatically when starting TCP/IP applications").
- Click OK, then click Apply Now.
For a PPPoE connection
- Open System Preferences.
- Click Network.
- From the Show menu ("Configure" menu prior to Mac OS X 10.1), choose Built-in Ethernet or AirPort.
- Click the PPPoE tab, then PPPoE Options.
- Deselect the checkbox for "Connect automatically when needed" (or in earlier Mac OS X versions, "Connect automatically when starting TCP/IP applications").
- Click OK, then click Apply Now.