Weidmuller Wireless Ethernet Modem & Device Server WI-MOD-E-G/A User Manual
Rev.
2.16
www.weidmuller.com
34
3.8 - Normal Operation
After addresses are configured, the units are ready for operation.
Refer to section 1 for an explanation on the operation of a Bridge and Router.
Bridge Operation (Transparent Network)
A bridge connects several Ethernet networks together, and makes them appear as a single Ethernet network to higher
protocol layers.
By default, the WI-MOD-E is configured as a transparent bridge. When a transparent bridge is started, it learns the
location of other devices by monitoring the source address of all incoming traffic. Initially it forwards all traffic between the
wired Ethernet port and the wireless port, however by keeping a list of devices heard on each port, the transparent bridge
can decide which traffic must be forwarded between ports - it will only transfer a message from the wired port to the
wireless port if it is required.
A bridge will forward all Broadcast traffic between the wired and wireless ports. If the wired network is busy with broadcast
traffic, the radio network on the WI-MOD-E can be unnecessarily overburdened. Use filtering to reduce broadcast traffic
sent over the radio. Refer to section 3.19 - “Filtering” for how to configure a filter.
By default, a transparent bridge does not handle loops within the network. There must be a single path to each device on
the network. Loops in the network will cause the same data to be continually passed around that loop. Redundant
wireless links may be set up by enabling the bridge Spanning Tree Protocol (see section 3.5 - “Spanning Tree Algorithm”
for more details).
Router Operation (Routed Network)
A router joins separate IP sub-networks together. The router has different IP addresses on its wired and wireless ports,
reflecting the different IP addresses of the separate Ethernet networks.
All of the devices in these separate networks
identify the router by IP address as their gateway to the other network. When devices on one network wish to
communicate with devices on the other network, they direct their packets at the router for forwarding.
As the router has an IP address on each of the networks it joins, it inherently knows the packet identity. If the traffic
directed at the router cannot be identified for any of the networks to which it is connected, the router must consult its
routing rules as to where to direct the traffic to. For details on configuring routing rules, see section 3.18 - “Routing”.
3.9 - Radio Configuration
Figure 27 - Radio Config
