INSYS EDGE 5.0 Series, Manual

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Connection INSYS GPRS/EDGE 5.0 serial
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5.5 Setup and Disconnetction of a TCP Connection
5.5.1 Overview
A connection with the APN (access point to the GPRS/EDGE network) is required
for a TCP communication in the GPRS/EDGE network (only the GPRS network is
mentioned in the following for reasons of simplicity) first; this is called “GPRS At-
tach”. An IP address is assigned with the GPRS Attach. Then, the connection be-
tween application client and server will be established; this is called “TCP Con-
nect”. It is now possible to transmit data. After the data transmission is finished,
the TCP connection can remain established or be disconnected. The disconnection
performs a “TCP Disconnect” first to disconnect the TCP connection. Then, the
connection to the GPRS network can also be disconnected; this is called “GPRS De-
tach”. The following figure shows the different levels of the connection setup and
disconnection:
TCP Connect
Communication
TCP Disconnect
GPRS Attac
h
TCP Connection
GPRS Detac
h
GPRS Connection
GPRS Attach
The connection to the APN is established. An IP address is assigned and the charge
counter (charge counter fort he incurred data volume) is started.
TCP Connect
The TCP connection between application client and server is established.
TCP Disconnect
The TCP connection between application client and server is disconnected.
GPRS Detach
The GPRS connection is disconnected. The IP address is returned and the charge
counter is stopped. The used volume will be rounded to the next data block. For a
data block size of 100 kB for example, 100 kB will be charged, even if only 10 kB
have been transmitted.