Iridium SHOUT ns General Description Manual page 75

Dial-up Data (DAV)
Direct Internet
SBD
SMS
RUDICS
Landline
Modem
The Iridium dial-up data service, as shown in Figure C3, functions in much the same way
as the PSTN dial-up connectivity. From the perspective of a computer, the Iridium modem is
just another external modem. The only difference is that the dialed telephone number must
conform to the international dialing pattern used by Iridium. When a data call is placed, the
Iridium modem actually dials and initiates a connection with the Iridium gateway through the
Iridium satellite constellation. Since the Iridium modem is requesting to establish a data
connection, the switch at the gateway routes the call through another modem. The modem
at the Iridium gateway then dials into and connects to another modem at the other end.
Figure C3 illustrates how an Iridium dial-up data service call is routed. The handshaking and
protocols established between the modems independent of the Iridium network.
For those ISU-to-ISU dial-up calls where data transmission delay is critical such as the
application of TCP/IP protocol, DAV should be considered in the design. This option eliminates
NAL Research Corporation (451-01001.B)
AZ, HI or Fucino
PSTN
SBD, SMS
(e-mail)
Figure C2. Iridium Network Data Capabilities.
RUDICS
Server
Internet
Dial-up Data (DAV)
SMS, SBD
IP
Address
75