Using the Terminal Server

The UTM-1 appliance includes a built-in terminal server (also called a device server), which allows you to Internet-enable legacy RS-232 serial devices by simply connecting them to the appliance's Serial port; there is no need for hardware modification or additional equipment. By adding IP connectivity to your serial devices, the terminal server enables remote monitoring, diagnostics, and management of the devices.

The terminal server can be used in the following modes:

• Passive Mode. The terminal server accepts connections from an external Telnet client, and relays traffic to and from the appliance's Serial port. This mode allows Telnet clients to remotely access devices attached to the appliance's Serial port.
• Active Mode. The terminal server connects to an external Telnet server, and relays traffic to and from the appliance's Serial port. This mode affords devices attached to the appliance's Serial port permanent access an external Telnet server.

  Note: You can enable tunneling of serial RS-232 data over the Internet or VPN, by configuring one UTM-1 appliance in passive mode and another in active mode.

The terminal server can be used in conjunction with VPN connectivity, to enable secure transmission of RS-232 data between the serial devices and the Telnet client or server.