Insys GPRS 5.0 serial 11-02-01-03-10.014 Manuale Utente
Codici prodotto
11-02-01-03-10.014
Information Regarding GPRS
INSYS GPRS 5.0 serial
66
Mai 06
8.8.2.2 Transmission of user data with reference data acknowledge
of the remote terminal
Application
/
GPRS Modem
control centre
reference data: 15
TCP/IP PUSH: 40
reference data
: 0
TCP/IP ACK:
40
reference data
ACK: 2
TCP/IP PUSH
: 40
reference data: 0
TCP/IP ACK: 40
Total: 177 byte
8.8.2.3 TCP Keep Alive
Some GPRS providers terminate the connections when they are inactive. Vodafone, for
example, terminates the connection after approximately 30 minutes without data trans-
fers. For this reason, applications that exchange data in larger intervals should consider a
Keep Alive timer. The TCP stack generates an empty TCP message in adjustable intervals
which the TCP remote terminal responds to. This will satisfy the expectations of the pro-
vider regarding the amount of data. The INSYS GPRS 5.0 serial provides this function.
The application will not notice this action.
Some GPRS providers terminate the connections when they are inactive. Vodafone, for
example, terminates the connection after approximately 30 minutes without data trans-
fers. For this reason, applications that exchange data in larger intervals should consider a
Keep Alive timer. The TCP stack generates an empty TCP message in adjustable intervals
which the TCP remote terminal responds to. This will satisfy the expectations of the pro-
vider regarding the amount of data. The INSYS GPRS 5.0 serial provides this function.
The application will not notice this action.
Application
/
GPRS Modem
control centre
reference data: 0
TCP/IP PUSH: 40
reference data
: 0
TCP/IP NACK
: 40
Total: 80 byte