A satisfying testing experience on a rainy Sunday


The problem statement: an annoying pause

The issue was really quite simple: on all devices in a family home (three laptops, two tablets and one smart phone) the display of videos through the internet (whether through Youtube or another channel) was very slow. I was shown a video on the iPad. The beginning of the video was loaded, was paused after a few seconds because more of the video had to be loaded, the video ran on for a couple of seconds and then was paused again to load more of the video. This went on and on so viewing a twenty minute video was a very annoying, gruelling, experience. The lagging video display had been frustrating the family for quite some time.

I was visiting the family. It was a Sunday afternoon. It was pouring.

The system setup

There is a home network to which, through a wireless router, the three family laptops all running a Windows operating system are connected. Also using the wireless router are two tablets, one iPad 2 and another unidentified tablet running some version of the Android operating system. Also, one (Android) smart phone will probably use the wireless router for internet access. Not all devices are switched on at the same time. The wireless router is linked to a DSL modem. Both modem and router are of the Cisco brand, types of modem and router were not investigated.

First inference

Since all devices suffered from the same lags in loading and displaying videos I concluded that neither the operating systems nor the devices were the first candidates for investigation. In fact the speed of the internet connection would be a good starting point for the investigation.

The requirements

At that point two things needed to be established. One, the expected speed of the connection and two, the actual speed of the connection. The expected speed of the connection was established by looking up the service contract with the internet provider. The download speed should be 50 Mbps.

The first test: how fast is the internet connection?

With this in mind it was time to investigate the actual speed. This could be done with an online tool on the website of the provider. But since I wanted a second tool to verify the results of the tool offered by the provider I found a nifty little iPad app that also measured the speed of the internet connection.

Using these two applications, one on one of the laptops and one on the iPad it was established that the download speed of internet connection was at least fifteen times slower than the speed promised by the provider. According to the tool offered by the provider was about 3 Mbps (several measurements in a time frame of a couple of minutes) and the speed according to the iPad app was even less; 0,5 Mbps ( (again several measurements in a time frame of a couple of minutes).

Notice that there is quite a difference between the measurements with the respective tools. I decided not to bother with the difference since a) it would probably be impossible to find the cause of the difference and b) because both measurements clearly indicated that the connection speed was (very) low. The classification high, medium, low, very low contained enough granularity for me at that time.

Another thing that struck me was the the upload speed was actually higher than the download speed. Normally, in DSL lines, the download speed is significantly higher than the upload speed. I did not investigate into this further but it may have been a pointer towards the reason for the problems.

I was told that the wireless router had fallen at least once. The owner of the router thought that that may have caused a defect in the router.

The second test: is the wireless router the cause of the problem?

To eliminate the router as a cause I reset it a couple of times, without any effect on the download speed. Then I decided to take the router out of the equation. I connected the laptop directly to the modem. Should the router be the cause of the troubles then with this new setup I should have a good download speed. It was possible to connect the laptop to the modem but there was no internet connection. This was the point at which I was baffled a little bit. I thought connecting the laptop to the modem should be a plug-and-play thing. But apparently this was not the case.

To see if I could get the internet connection working through the modem I rebooted the laptop. Without success. Then I started paying attention to the suggestions that Windows offered by which I should be able to fix the connection. One of them was to adjust the DHCP settings. Since I am not a wizard at network settings, I decided to leave that alone at first. One other suggestions was to reset the moden.

The solution: beaten by Windows

Why hadn’t I thought of that before? I was beaten to the chase by Windows! In the early days of DSL I had tinkered with modems and routers for the better part of an afternoon to get the network going. I remembered having tried all sorts of boot and reset sequences. The one I still use infrequently is to shut down the router, shut down the modem, boot the modem, wait till it’s fully functional, then boot the router, wait till the router is online and then start the pc or laptop.

I skipped the ‘internet connection through the modem‘ test and applied the somewhat familiar boot sequence. Then I grabbed the iPad and hit the speed test application. It now showed a very nice and satisfying download speed of about 20 Mbps. I was happy to report that the internet connection speed had just increased by a factor 40.

The deliverables: happiness despite the rain

But was that 20 Mbps speed really satisfying? Our requirement said that the speed in fact ought to be 50 Mbps. But then I remembered that DSL connections seldom reach the specified speed. It has something to do with the distance from the switch, the number of houses using that connection, possible the quality of the ethernet cables and interference from other devices. Interference could not be ruled out because the modem and the router were close to a phone, a television, a dvd player and such.

I could have done many other tests in search for the cause of the issue. I could have finished the ‘internet connection through the modem‘ test. I could have upgraded the firmware of the router and the modem and test the effect of that. I could have tried a different ethernet cable. But the result of the session was reasonable and spending more time on testing seemed like a waste. I handed the iPad to the owner and he conjured up the video – a cooking instruction video – that had been plaguing him for quite some time. This time it ran without a flaw. As an extra test on the laptop I loaded a lengthy video in Youtube (Goranka Bjedov – Using open source tools for performance testing). Goranka came through clear and without a hitch.

Though the actual cause of the error had not been found I was happy to hand to the family two testing products that may help them in the future: 1) a nice little iPad tool to measure the internet connection speed and 2) a procedure to reboot the internet connection just in case.

I like to think I delivered exactly what was needed.


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