VEGA INSYS Modem GPRS 5.0 - Manual (Page 86)

GPRS General INSYS GPRS 5.0 serial
86
8.3 TCP Transparent
This function represents the main characteristic of the extended function. By
means of the integrated TCP/IP stacks, the INSYS GPRS 5.0 serial functions as
“modem emulation” for the application; the user data are provided transparently
via the serial interface ("TCP transparent" connection).
There is no need for the application to process any additional protocol stacks.
To establish TCP connections to the INSYS GPRS 5.0 serial, it is necessary to access the
IP address of the GPRS device. This function must be supported by the network opera-
tor or the provider.
Mobile application
TCP
PPP/IP
PPP/IP
GPRS Bearer
IP
GPRS Bearer
Router
(GGSN)
IP IP
application server
TCP
IP
GPRS Net radio components and internal GPRS net
IP
INSYS GPRS device
Application
remote site
µController
GSM/GPRS
Engine
Note
The integrated TCP/IP stack will establish a new GPRS connection
for each “TCP transparent” connection, i.e. after the
end/termination of the “TCP transparent” connection follows the
calculation of the GPRS provider, where the data accumulated until
then is rounded to the next billing unit.
This does not apply if the operating mode TCP Listen is activated; in
this case, the GPRS context is preserved after the TCP connection is
terminated, which means that the billing takes place only for a so-
called forced billing by the provider (once a day) or during a con-
trolled termination of the GPRS context by the device itself (periodic
login/logout or device restart, termination of the connection and
reconnection due to failed PPPIPCHECK, or deactivation of TCP Lis-
ten).