To communicate with a dial-in server, you need to gather information about the server. Then edit a few files. Most significantly, you must configure the communications requirements of all dial-in servers that the dial-out machine needs to call. You can specify options about a dial-in server, such as an ISP phone number, in the /etc/ppp/options.ttyname file. However, the optimum place to configure peer information is in /etc/ppp/peers/peer-name files.