2.2 Configuration for Asynchronous Connections
2.2.6 Basic async configuration—router preparation

To make a successful asynchronous connection, you need to configure the modem and the access server properly. On the access server (router), use the commands in Figure to configure the line to which the modem is attached. (see Table for command descriptions.) Software flow control (xon/xoff characters) is not recommended with modems and Cisco routers.