To allow a connection to the FireBrick you have to decide on a hostname. This is not a DNS hostname and is more like a login or username. It can be anything you like. You can pre-agree with your carrier the hostname they will use and the IP address of your LNS. When the connection arrives the protocol includes the hostname and a secret (i.e. a password. The hostname allows the FireBrick to check which connection details apply). The secret is used so that the FireBrick can confirm its identity, at present it is not checked on incoming connections by the FireBrick. You should use allow or other means to ensure connections are valid if needed.

The FireBrick can be configured with many hostnames, which would typically be used for different carriers to connect. You can also use the hostname to separate different types of connection - for example, in the UK, BT have 20CN IPStream, and 21CN WBC connections which typically need separate monitoring and traffic shaping. You could even use the hostname to separate different grades of service, or, if the ISP is providing wholesale connections, for different ISP customers.

The incoming connection configuration includes the password, and the RADIUS servers to use to validate the users, and various defaults that apply to the PPP connections. Most of these defaults can be set by the RADIUS server as well, but it can be useful to make the RADIUS configuration simple to hav defaults in the FireBrick config.

Taking one step back, the choice of LNS and hostname that the carrier uses when sending the connection to the ISP can eitehr be pre-configured, or more usefully it can be based on a RADIUS request (sometimes called platform RADIUS). This allows the ISP to decide on a per-connection basis the tunnel endpoint details and steer sessions. The FireBrick can act as a platform RADIUS server, answering all queries to steer sessions to the correct LNS and hostname.