34 | About the Radio
Aprisa SRi User Manual 1.1.0
Static IP Router
The Aprisa SRi works in the point-to-multipoint (PMP) network as a standard static IP router with the
Ethernet and wireless / radio as interfaces and serial ports using terminal server as a virtual interface.
The Aprisa SRi static router is semi-automated operation, where the routing table is automatically created
in the base station and populated with routes to all remote radios in the network during the registration
process and vice versa, where the routing table is automatically created in remote radios and populated
with routes to base station during the registration process. Updates occur when remote is disconnected from
network for any reason, with the routing table updated in a controlled fashion.
Also, in decommission operation, the base station routing tables are completely flushed allowing an
automatic rebuild. This avoids the user manually inserting / removing of multiple static routes to build /
change the routes in the network which might be tedious and introduce significant human error. The Aprisa
SRi works as a static IP router without using any routing protocol and therefore does not have the overhead
of a routing protocol for better utilization of the narrow bandwidth network.
In addition to the semi-automated routes, the user can manually add / remove routes in the routing table
for the radio interface, Ethernet Interface and for routers which are connected to the radio network.
The Aprisa SRi base station is used as a gateway to other networks. Thus, a configurable IP address default
gateway can be set using a static route in the routing table with a destination IP address of the destination
network address. It is recommended to use a real network IP address (actual device IP) for the gateway and
not 0.0.0.0.
The Aprisa SRi sub-netting rules distinguish between the wireless interface and the remote Ethernet
interface where RTUs are connected. The entire wireless network is set on a single IP subnet, while each
Aprisa SRi
remote’s Ethernet interfa
ce is set to a different subnet network. In this way, the user can easily
distinguish between the remote radios subnet IP addresses.