Nortel Networks 553-3001-211 manual Call disconnection DAC, Call disconnection modem

Page 450 of 894 NT7D16 Data Access card

Table 153

Connect and disconnect protocol (Part 2 of 12)

Mode of
operation Interface application	Comments
	Outbound modem pooling:
	Local DM user calls to the outbound modem
	access number.
	DAC answers the outbound call and drives DTR
	ON.
	Modem receives DTR and prepares to receive
	commands.
	Local DM user enters the proper commands for
	calling the remote modem.
	Remote modem answers; data call established.
	Call disconnection (DAC):
	DAC drops DTR if the local DM user drops the
	call. The modem must drop DCD.
	DAC drops DTR if the remote modem sends a
	long break or three short breaks. The modem
	must drop DCD.
	Call disconnection (modem):
	Modem drops DCD (DCD OFF for 100 ms or
	more). The DAC drops DTR and disconnects the
	local call.
	Modem drops DSR (DSR OFF for 100 ms or
	more). The DAC drops DTR and disconnects the
	local call.

553-3001-211 Standard 2.00 September 2004