Cisco Systems DC-157 manual Closing Modem Connections, DC-162

Modem Signal and Line States

Signal and Line State Diagrams

Closing Modem Connections

Note The modem cts-requiredcommand was replaced by the modem printer command in Cisco IOS Release 12.2.

To configure a line to close connections from a user’s terminal when the terminal is turned off and to prevent inbound connections to devices that are out of service, use the following command in line configuration mode:

Command	Purpose
Router(config-line)# modem cts-required	Configures a line to close connections.

Figure 28 illustrates the modem cts-requiredcommand operating in the context of a continuous CTS signal. This form of modem control requires that the CTS signal be high for the entire session. If CTS is not high, the user input is ignored and incoming connections are refused (or sent to the next line in a rotary group).

Figure 28 EXEC and Daemon Creation on a Line Configured for Continuous CTS

Idle state

DTR high, watching

CTS

CTS raised

Close connection,

DTR low for

5 seconds

Hang up

		CTS lowered
DTR going				DTR high,			Ready
				watching
low
				CTS
	User-typed
				Incoming network
	activation
			Create		connection
	character
			EXEC			Create
					daemon
Ready		DTR high,					Ready
				DTR high,
and		watching
				watching			and
active		CTS
				CTS			active
		CTS lowered		CTS lowered or
		or exit
				network
				connection				S1004a
				closed

Cisco IOS Dial Technologies Configuration Guide

DC-162