Nortel Networks Circuit Card - Manual (Page 462)

Page 462 of 906 NT7D16 Data Access card
553-3001-211 Standard 3.00 August 2005
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.
Table 158
Connect and disconnect protocol (Part 2 of 12)
Mode of
operation
Interface application Comments