About the Radio | 45
Aprisa SRi User Manual 1.1.0
The NAT session table of remote-
1 session ID #1 shows that the public interface RF port address can’t be
used in the NAT function or in NAT Address Map Table configuration as it is reserved for the radio access
(e.g. management access, etc). This line is just for explanation purposes as in SuperVisor it will not be
shown in NAT session table since no NAT translation i
s made as it’s not part of the Address Map Table
configuration table.
Session ID #2 and #3 shows the inbound and outbound session translation when the SCADA master accesses
RTU-1 and vice versa. From the SCADA master perspective, RTU-1 public address is 192.168.2.4
(as it doesn’t
know the real address 10.10.1.2 of RTU-
1 which is ‘hidden’ behind the NAT). As explained above, SuperVisor
will not show session ID #2 and #3 in one line as these inbound / outbound transactions are considered as
one session.
NAT translates the inbound session public RF port destination IP 192.168.2.4 to 10.10.1.2 on Eth port, the
real private IP destination of RTU-1. The source address of SCADA master 172.16.1.1 remains unchanged
during the inbound NAT translation as shown in session ID#2.
Outbound session #3 shows the response of RTU-1 to SCADA master and NAT translation of Eth port private
source address 10.10.1.2 to 192.168.2.4 on RF port public source address. The destination address of SCADA
master 172.16.1.1 remains unchanged during the outbound NAT translation.
