10 S&C Instruction Sheet 1074-510
Description
Once the individual data networks are established, you should plan the IP addressing
scheme. In Figure 1 on page 8, each SpeedNet ME Radio host ID is 1 and each automatic
switch control host ID is 2. Following a numbering scheme such as this will make it easier
to keep track of which IP addresses are used for each device.
The SCADA network in this example uses the 192.168.203.0 subnet. This subnet is
different than the subnets used for the Ethernet segments. The wireless interface of the
SpeedNet ME Radio from Subnet 1 is assigned an address of 192.168.203.1. The wireless
interface of the SpeedNet ME Radio from Subnet 2 is assigned an address of 192.168.203.2.
The wireless interface of the SpeedNet ME Radio from Subnet 3 is assigned an address
of 192.168.203.3.
You may find it helpful to draw a diagram as a planning aid and reference guide when
designing your SCADA network.
Routing Options
The SpeedNet ME Mesh End-Point Radio is an end node radio and does not participate in
building the mesh network. It does however, connect to a SpeedNet Radio mesh network
that is capable of providing secure, long range communication with high-message rates.
SpeedNet ME Radios provide a point-to-point wireless connection between two or more
separate Ethernet subnets. Data is then routed between the Ethernet subnets. Route
information can be entered manually, or can be processed automatically by Ad hoc
On-demand Distance Vector (AODV). See Figure 2 on page 9 for an example of a wireless
network using SpeedNet ME Radios with AODV. AODV Routing is a routing protocol for
mobile ad hoc networks and other wireless ad hoc networks. SpeedNet ME Radios use a
proprietary AODV routing system, that works dynamically to maintain message routing. It
generates fewer transmissions, and conserves network capacity. In the case of SpeedNet
ME, AODV will be limited to discovering and establishing the best possible point-to-point
link. SpeedNet ME Radios will not act as message relays for other nodes in the network.
Using Static Routes
The routing mode to use (static routes vs. AODV) will be determined by the present
configuration of the network with respect to routing mode (whether it is using static
routes or AODV). The radios do not support a mixture of static routes and AODV routing.
See Figure 3.
SpeedNet ME 1
Ethernet Interface: 192.168.1.1
Wireless Interface: 192.168.3.1
IP Address: 192.168.1.2
SpeedNet ME 2
Ethernet Interface: 192.168.2.1
Wireless Interface: 192.168.3.2
IP Address: 192.168.2.2
Figure 3. Wireless network using SpeedNet ME Radios with static routes.
