Nortel Circuit Card Installation Manual page 464

Page 464 of 906
Table 158
Connect and disconnect protocol (Part 4 of 12)
Mode of
operation Interface application
Mode 3 Inbound Hotline modem
pools (with forced DTR)
Use this mode with Hayes
1200 modem.
Mode 4 Inbound and Outbound
Gateway access
553-3001-211 Standard 3.00
NT7D16 Data Access card
August 2005
Comments
Inbound Hotline modem pooling:
The DAC operation is identical to mode 1 except
that DTR is always forced ON (except during
disconnect).
Call disconnection:
Disconnection is identical to mode 2.
Inbound Gateway connection protocol:
Gateway raises DCD to initiate connection.
DAC responds by driving DTR ON.
Gateway does not have to turn DSR ON.
However, toggling DSR or DCD from ON to OFF
causes the DAC to disconnect the call.
Gateway user sends <CR> to the DAC.
DAC autobauds and sends the initial prompt to
the Gateway.
Outbound Gateway connection protocol:
Local DM user calls the DAC that is connected to
a Gateway.
DAC answers the data call and drives DTR ON.
Gateway receives DTR and prepares to receive
commands.
Local DM user is now transparently connected to
the Gateway.
Gateway is expected to drive DCD ON within 35
seconds. If the Gateway fails to do so, the DAC
drops DTR and the call.