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Cooper Bussmann 245U-E Wireless Ethernet Modem & Device Server User Manual
89
Rev Version 2.19
4.7 Testing Radio Paths
Connection and Signal Strength
The general procedure for radio range testing a link is fairly simple. Configure two units to form a link using
automatic radio rates. Install the access point at a fixed location. Take a laptop computer and the client to each of
the remote locations, and analyze the link using the Connectivity webpage. If a beacon is heard from the access
point, the client will update its Connectivity webpage with the received signal strength of beacon messages from
the access point.
If the signal is strong enough, a link may be established and the Connectivity webpage of the access point may be
opened. If the link is weak, the LINK LED will turn off and the remote Connectivity webpage of the access point will
fail to load. Using this procedure, the signal strengths of units at both locations may be analyzed, and traffic is sent
between the units while remote webpages are opened.
Iperf Throughput Test
A more thorough test of radio paths is a throughput test, which will check the amount of data that can be reliably
achieved via the wireless link. There are a number of software tools that you can use to check the data throughput,
such as FTP (File Transfer Protocol), Iperf, and Qcheck. The preferred application is “Iperf,” which has been
configured in each modem and can be enabled to perform this test. It can also be run externally using laptops at
either end of the radio link. The Iperf/Jperf application can be downloaded from http://sourceforge.net/projects/iperf/.
All of the above applications measure the raw data throughput. From this you can determine the amount of
interference from the measured and calculated data throughput levels. The way Iperf works is that a server
is enabled at one end of the link and a client at the other. The Iperf client then passes data over the link and
calculates and displays the throughput accordingly.
The Iperf server can be run internally on the modem by enabling this feature on the Advanced Radio page of one of
the modems (see “4.4 Throughput Test”). It can also be run externally on a PC or laptop connected at each end of
the radio link. For a detailed procedure on using Iperf to externally check radio data throughput, see “Appendix D -
EXTERNAL IPERF TEST.”
The internal Iperf is a basic cut down version of the standard Iperf and should be used as a guide only. For a more
comprehensive test, Iperf should be run externally using laptops or PCs at each end of the Wi-Fi link.
Internal Radio Test
The module also has an internal Radio Path test that will allow you to perform a basic radio path test without the
need for a laptop or PC. Two tests that can be run—RSSI, and Throughput. The throughput test can be disabled
independently from the RSSI test, but disabling the RSSI test will turn off both tests. Typically, the radio path test
should be enabled at a modem configured as a client or station
NOTE The Radio Path Test feature should not be enabled on a live system. It is intended for testing only.
Figure 92 Radio Path Tests
