Modemulator User Guide
Page
31
of
113
Incoming Calls
Incoming PSTN calls or incoming cellular calls will route through the
host
Modemulator’s Terminal port to
the legacy application software when a connection completes.
If the
host
Modemulator has a cellular connection already in-progress with a
remote
Modemulator, the
host
Modemulator will de-assert the RS-232 DTR signal to the attached dial-up
modem to prevent the attached dial-up modem from answering an incoming PSTN call.
If the
host
Modemulator has a PSTN connection already in-progress with a
remote
dial-up modem
and a
remote
Modemulator attempts to contact the
host
Modemulator, the
remote
Modemulator
will report
NO DIALTONE
.
If the
host
Modemulator has a cellular connection already in-progress with a
remote
Modemulator, and another
remote
Modemulator attempts to contact the
host
Modemulator, the
remote
Modemulator will report
NO DIALTONE
or
BUSY
or
NO CARRIER
.
The following diagram illustrates a simplified peer-to-peer legacy system using two Modemulators, cellular
peer-to-peer service, two dial-up modems, and PSTN service.