Table 180 connect and disconnect protocol – Nortel Networks Circuit Card 311 User Manual

Page 445

Operating modes

445

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for connect

and disconnect protocol.

Table 180
Connect and disconnect protocol

Mode of
operation

Interface application

Comments

Mode 0

Inbound and Outbound
modem pools

For inbound modem pools,
most dumb modems may be
used.

For outbound modem pools,
only smart modems
(auto-dialer) may be used.

Outbound modem pooling:

Modem sends ring/no ring cycle (2 seconds ON, 4
seconds OFF) to initiate connection.

DAC responds by driving DTR ON within the first ring
cycle.

Modem responds by answering the incoming call and
driving DCD ON within 35 seconds.

If modem does not drive DCD ON within 35 seconds,
the DAC drops DTR and goes idle.

Remote DTE sends to the DAC. The DAC
autobauds and sends initial prompt.

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.

Nortel Communication Server 1000

Circuit Card Reference

NN43001-311

01.04

Standard

Release 5.0

23 May 2008