Telit Wireless Solutions Easy GPRS - Manual (Page 17)

Easy GPRS User Guide
80000ST10028 Rev. 1 - 14/03/07
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 17 of 37
2 Enhanced Easy GPRS Extension
2.1 Overview
The Easy GPRS feature allows the
Telit module
users to contact a device in internet and establish with
it a raw data flow over the GPRS and Internet networks.
This feature can be seen as a way to obtain a "virtual" serial connection between the Application
Software on the Internet machine involved and the controller of the
Telit module , regardless of all the
software stacks underlying.
An example of the protocol stack involved in the devices is reported:
This particular implementation allows to the devices interfacing to the
Telit module
the use of the GPRS
and Internet packet service without the need to have an internal TCP/IP stack since this function is
embedded inside the module. The Easy GPRS overcomes some of the known limitations of the
previous implementation and implements some new features such as:
• Keep the GPRS context active even after the closing of a socket, allowing the application to keep
the same IP address;
• Also Mobile terminated (incoming) connections can be made, now it is possible to receive
incoming TCP connection requests;
• A new internal firewall has been implemented in order to guarantee a certain level of security on
internet applications.
Remote
Controller Device
Device (Internet)
Local Remote
Application Application
TCP/UDP
EASY EASY TCP/UDP
GPRS GPRS
IP IP IP IP
Serial Data
Line on
Driver Board
L2 L2
V.24 V.24
L1 L1
Telit
module networks
Firewall
<<<---------------------------------- Virtual Serial link ---------------------------------->>>
network interworking