Modemulator User Guide
Page
26
of
113
Disconnect the dial-up modem from the application hardware serial port, and connect the Modemulator to
the application hardware serial port. The application hardware will now use the Modemulator for all
communications.
Outgoing Calls
In a peer-to-peer system the
host
Modemulator or any
remote
Modemulator may initiate a connection.
To initiate a connection from an
originating
Modemulator to an
answering
Modemulator, a dial
command is sent by the legacy software to the
originating
Modemulator. The
originating
Modemulator
will search its dialing directory for an entry containing the phone number from that dial command.
If an entry for that phone number is found in the dialing directory, the
originating
Modemulator
will open an IP connection to the IP address of the
answering
Modemulator. The
originating
Modemulator and the
answering
Modemulator will then send call-progress messages to the legacy
application
software that mimic those of a dial-up modem. If the
answering
Modemulator is
configured to auto-answer or if the application
software
issues an answer command, the connection
will complete, which emulates the behavior of dial-up modems.
If the
answering
Modemulator does not auto-answer or manually answer, the connection will
time-out, which emulates the behavior of dial-up modems.
The
originating
Modemulator will report
NO DIALTONE
or
BUSY
or
NO CARRIER
if the
answering
Modemulator already has a connection in-progress with another Modemulator.
The
originating
Modemulator will report
NOT FOUND
if an entry for that phone number is not
found in the dialing directory, and a dial-up modem is not attached or not available. See
Compatibility With Dial-up Modems
for information about attaching a dial-up modem to a
Modemulator.
If an entry for that phone number is not found in the dialing directory, and a dial-up modem is
attached and available, the
originating
Modemulator will forward the dial command to the
attached dial-up modem which will dial the number via the PSTN. See
for information about attaching a dial-up modem to a Modemulator.
The legacy software sends the same type of command to initiate both cellular and analog connections, and
receives the same type of responses. This makes the type of connection indistinguishable and transparent
to the legacy software.
Incoming Calls
In a peer-to-peer system the
host
Modemulator or any
remote
Modemulator may answer a connection.
Incoming cellular calls will route through the
answering
Modemulator’s Terminal port to the legacy
application software when a connection completes.
If the
answering
Modemulator does not have a cellular connection already in-progress with
another Modemulator, the
answering
Modemulator will accept the IP connection from the
originating
Modemulator. The
originating
Modemulator and the
answering
Modemulator will
