User's Manual

Elpro Technologies 450U-E Wireless Ethernet Modem & Device Server User Manual
Rev Version 1.0.12-Beta7 www.cooperbussmann.com/wirelessresources 31
Bridge / Router Operation 3.9
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 450U-E is configured as a transparent bridge. When a transparent bridge is started, it learns the location of
other devices by monitoring the MAC 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 450U-E can be unnecessarily overburdened. Use filtering to reduce broadcast
traffic sent over the radio. Refer Section 3.14 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 3.7 Spanning Tree Protocol
Algorithm
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 sub 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 to 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 3.13 IP Routing
Radio Configuration 3.10
Figure 35 - Radio Config
The Radio Configuration page is where configuration parameters associated with the radio can be adjusted or configured.
The first time out of the box configuration will run a configuration wizard that will step you through some radio questions
that will allow you to select radio configuration for your country of operation and license.
The factory-default parameters of the radio will be set to values that will allow the radio to be powered up safely, without it
interfering with radio equipment that may be available in the country of operation. I.e. transmit and receive frequencies will
be set to zero.
After the initial out of the box configuration you will be able to configure available radio parameters by selecting the
page. When all changes are made, you will & Activate the changes.