Siemens SINAUT ST7 System Manual page 94

Network structures and topologies
2.2 Configurations
IP-based communication via GPRS with higher security
Control center
IP address
Station
Figure 2-6
94
SINAUT
ST7cc/sc
TIM
4R-IE
Industrial
Ethernet
VPN tunnel
Internet
Firewall
Dynamic
MD741-1
S7-300 with
TIM 3V-IE
GPRS with higher security via MD741-1 modem
Security
Module
SCALANCE S
DSL router
Dedicated line
to Internet, e.g.
DSL connection
with flat rate and
Firewall
preferably
fixed IP address
VPN tunnel
GPRS network
Firewall
Dynamic
MD741-1
IP address
S7-300 with
TIM 3V-IE
Station
System Manual, 07/2009, C79000-G8976-C178-07
Station control system