System Administration Guide: Network Services

Enabling Dialback Through the Chat Script

Some companies set up dial-in servers to handle calls from remote computers. For example, your company might have a dial-in server with a dialback modem that employees can call from their home computers. After the dial-in server identifies the remote machine, the dial-in server disconnects the link to the remote machine and then calls back the remote machine. The communications link is then reestablished.

You can facilitate dialback by using the \H option in the Systems file chat script at the place where dialback should occur. Include the \H as part of an expect string at the place where the dial-in server is expected to hang up.

For example, suppose the chat script that calls a dial-in server contains the following string:


The UUCP dialing facility on the local machine expects to receive the characters, INITIATED, from the dial-in server. After the characters, INITIATED, have been matched, the dialing facility flushes any subsequent characters that the dialing facility receives until the dial-in server hangs up. The local dialing facility then waits until it receives the next part of the expect string, the characters ogin:, from the dial-in server. When it receives the ogin:, the dialing facility then continues through the chat script.

A string of characters does not need to directly precede or follow the \H, as shown in the previous sample string.