Specifying MODEM CONTROL and SIGNAL CONTROL

Specifying MODEM CONTROL and SIGNAL CONTROL

Introduction

The MODEM CONTROL and SIGNAL CONTROL characteristics are identical, except that MODEM CONTROL is only used with full MODEM CONTROL access servers, and SIGNAL CONTROL is used on all other access servers.

These characteristics enable or disable the use of MODEM CONTROL signals on a port. With MODEM CONTROL or SIGNAL CONTROL enabled, the access server automatically logs out the port whenever a loss of the DSR signal (if used) is detected or if the DCD signal (if used) is deasserted for more than 2 seconds. Furthermore, a user must log in to the access server successfully within 120 seconds, or the access server automatically disconnects the call. You should disable MODEM CONTROL or SIGNAL CONTROL when a port is connected to a device that does not use modem signals, or if the device cable does not support modem signals.

Logging Out the Port with DSRLOGOUT or LONGBREAK LOGOUT

With MODEM CONTROL or SIGNAL CONTROL disabled, you can enable the access server to log out a port when the attached device is turned off by enabling port characteristic DSRLOGOUT (see Specifying DSRLOGOUT in Chapter 9) or LONGBREAK LOGOUT (see Specifying LONGBREAK LOGOUT in Chapter 9).

Computer Interface

For computer interface connections, you need to enable MODEM CONTROL or SIGNAL CONTROL and configure the host to use the modem signals. This ensures that session status is passed between the access server and the host system, which is important to maintain security.

When a user connected to the access server logs out from a system, the computer terminates the session and deasserts the DTR signal. The access server interprets this condition as a loss of DSR and terminates the session.

However, when the access server terminates a session, the access server deasserts the DTR signal. The system interprets this condition as a loss of DSR and logs out the user. This occurs when you enter a DISCONNECT command from the access server user interface or turn the power off.

The MODEM CONTROL or SIGNAL CONTROL characteristic can only be configured in the permanent database; therefore, you cannot use the SET or CHANGE command to configure MODEM CONTROL or SIGNAL CONTROL.

Configuring Modem Signals 10-7