Test Methodology

With our testing methodology for network gear we try to remove as many variables as possible and to maintain consistency through multiple runs of the same tests.  We’re using two identical Lenovo ThinkPad machines as the “Server” and “Client” machines with the following specifications:

Lenovo ThinkPad E520

  • Intel Core i3 2350M (Dual Core / 2.3 Ghz) CPU
  • 4 GB (1x4GB) DDR3/1333 RAM
  • WD Scorpio Black (WD3200BEKT) 320 GB HD (7200 RPM/16 MB Cache)

Also, since the integrated Wi-Fi card in the ThinkPad is a bit on the older side and not 802.11AC compatible, I’ve used a pair of BrosTrend AC1 USB 3.0 Wi-Fi adapters for any of the Wireless testing. The AC1 USB Adapter is spec’d at speeds of up to 867 Mbps on 5Ghz and 300 Mbps on 2.4 Ghz and should be more than enough for our needs.

Of course, hardware is only half the equation for network testing and we still need a way to actually measure throughput, reliability and other important statistics.  While there are simple online bandwidth speed tests, there are just too many variables that could impact those tests from run to run.  For consistency sake, the machines will not be connected to the Internet at all and only networked with the test equipment and each other.  I’ve pulled together a few pieces of software that will give us a good overall picture of network performance.

First up is the ever useful ping utility test.  Anyone that’s done even basic network troubleshooting will be familiar with the ping command that is used to check connections between two machines.  This simple tool will test the reachability of a host on the network and measure round trip time for data sent from the host to the destination machine.  With this simple tool we can gather the minimum, maximum and average time needed to send a packet of data between the two machine machines as well as let us know if there are any packets lost in the process.

The second “tool” is actually a pair of great applications from Pete over at Totusoft.   We are using Totusoft’s LAN Speed Test (v3.5) paired with their LST Server software to obtain data throughput speeds between our LAN and WAN machines.  We could have just used LAN Speed Test to run file upload/downloads against a file share between the machines to gather Average, Minimum and Maximum Upload/Download speeds.  However, adding the LST Server into the mix pushes the upload/download test data into the target system’s memory as opposed to hard disk.  By doing this, we remove any impact the hard disk speeds/cache would have on the actual speed values.  While there is a free ‘Lite’ version of the LAN Speed Test (v1.3) available, at only $6 each (or $11 for a package of both), both LAN Speed Test and LST server are worth every penny.

Finally, to get a good understanding of wireless signal strength, we’re using a tool called NetSpot.  Free for home use, NetSpot offers an easy way to visualize just about everything there is to see about Wireless signals being broadcast in the test area.

With these three tests we can get a pretty good snapshot of network connectivity and throughput.  Initially I was manually running each test one at a time, but since there are so many tests that need to be run, I strung together a batch file to automate some of the testing that drops the results into log files that I can import into other tools for analysis. 

The batch file does the following:

  • Run 12 tests of 100 pings each from the Server to the Client computer and document the Minimum, Maximum and Average ping time as well as any dropped packets.
  • Run 12 upload and download tests between the Server and Client machines using LAN Speed Test and the LST Server.Each LAN Speed test uploads and then downloads a 10 MB file 10 times in a row and then calculates Average, Minimum and Maximum Speeds in Mbps that were achieved while uploading and downloading the files.

For the Signal Strength tests, it was simply a matter of firing up NetSpot and leaving the window open.  Since the app calculates Average Signal strength on the fly, I just snapped a screenshot after 10 minutes to capture the Minimum, Maximum and Average Signal strength of the Wireless networks in question.

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