User's Manual

CHAPTER 7
REPEATING FEATURES
Revised: 23 Jan 08 7-4 EST P/N AA107G
Path Cost
If more than one communication path to the Root Bridge is found, the 195Eg must determine which route to take based upon the
lowest Path Cost. The default path cost to all links in the 195Eg network is 100. If the Path Costs are equal then the lowest MAC
address will determine the priority route. In the ESTeem Mesh Network we want to directly control all data flow so do not want
the routes to be automatically determined.
Looking again at our Example in Figure 4, if we made no changes to the default path cost of 100 (note values in Figure 3) the
lowest path cost would be direct from the Remote Building to the Root Bridge (Plant Network).
Link Description Number of Routes Total Path Cost
Direct from Remote Building 1 100
Remote Build to Root Bridge Through Repeater 2 200
To configure the 195Eg to select the repeater as the primary radio path, set the path cost value for the direct link greater than 200 to
make this the primary radio path. The lowest path cost will identify the highest priority. The Model 195Eg will use this routing,
but also switch to direct communication if the repeater were to disappear.
Root Bridge
In any Access Point Repeater network consisting of more than two sites, one Model 195Eg should be designated as the Root
Bridge. Only one Model 195Eg can be designated as the Root Bridge in a given network and should be located where the majority
of the Ethernet data flow is processed. This site may be the Master location in a SCADA network or could be configured at a
repeater site. Selection is important because all Model 195Eg’s NOT configured as the Root Bridge will choose routing based
upon the Path Cost to the Root Bridge. If you have any question as to which site in your AP Repeater application should be the
Root Bridge, contact ESTeem Customer Support at 509-735-9092 or e-mail your application to [e-mail].
The Root Bridge will be selected in one of two ways: the Root Bridge can be manually set (recommended) during the configuration
of the Repeater Peer table (Figure 3) or the Root Bridge designation will default to the lowest MAC address of all the Model
195Eg’s in the network. The manual Root Bridge configuration is located in the “Advanced Settings” section.
Figure 3: Repeater Configuration Example