Intermittent Powerline Dropout

[DrMopp]

New member alert so apologies if stupid questions. I have Devolo DLAN500 Duo Powerline adapters with Router, STB and Laptop connected, one to each adapter. Never had any problems with Router to STB connectivity (adapters at opposite ends of the same room), but frequent dropouts on Laptop in another room. As far as troubleshooting, to date I have had three different routers from two different manufacturers, changed all cables, tested with another laptop running Win 7, and even (temporarily) replaced the Devolo's with Netgear adapters. When the dropout occurs I can switch over to a wireless adapter in the laptop which is still connected so not an ISP issue. Only thing left seems to be mains wiring or interference - no clue as to how to test or resolve so ideas welcomed.

 

[Riekopo]

I've been using different powerline adapters for years and have the same problem. My internet will randomly go out about once a day for like 30 seconds or a minute. I've never been able to figure out what's causing it. I assume it's the wiring in the house which is about 60 years old.

 

[DrMopp]

Hi, thanks, I'm sure it must be the mains wiring as everything else has been changed over the couple of years I've had the problem, but this property is only 8 years old.

 

[PolarBear]

Hi, thanks, I'm sure it must be the mains wiring as everything else has been changed over the couple of years I've had the problem, but this property is only 8 years old.

Just a shot in the dark - some electric companies send a signal down the power lines to tell any smart meters installed at customers' sites, that it's time to switch over to cheap rate.

If the drop occurs at the same time every day, when the tariff changes, this might be the reason.

 

[DrMopp]

Thanks, but it's not the same time every day, not even the same number of times every day, and occurs on some days more often than others. I have a third adaptor in another socket that never drops out - though it is in the same room as the router adaptor. Anyone know of any powerline monitoring software that might help trace this?

 

[shock]

Guys, I think I sussed the problem out!!

I had exactly the same problem with the following models. (the problem was driving me nuts so went through a lot of plugs!)
TP-Link AV200, TP Link TL-PA411KIT, Netgear Nano 500, Netgear 1200 ect.

The only device so far I haven't had a problem with was the Netgear XAV1301V2! 200mbps.
So I went and bought a ZyXEL PLA5206. Guess what that didn't drop connections either.

So what's common amongst them, all the earlier ones use a Qualcomm chip-set. The last two use Broadcom.

 

[DrMopp]

Don't think that's the issue in my case - I have tried Netgear sdapters with same result. Am currently testing Windows 7 PC attached to the second port on the Devolo Duo to see if it drops out simultaneously and, though only one drop out since I have had both connected, the Win 7 PC seemed to stay up - which obviously suggests cable, ethernet port or driver.....

 

[bachastain]

Because of this problem I've given up (for now) on Powerline devices as fundamentally flawed. I too get the once or twice per day dropouts. The dropouts last from 10 seconds to 2 minutes or so.

I have bought and tested about a half dozen different models and manufacturers and couldn't find a single set that didn't have these semi-regular dropouts.

Since the dropouts can be pretty short, I started running a test program that pinged itself, the router, and somewhere on the internet. Initially I had no idea where the losses where occurring.

I ignored losses of a small number of pings, concentrating on losses longer than 15 seconds.

In parallel I also ran ping tests on other PCs/laptops that were either ethernet cables or Wifi. In no case was the ping loss duplicated on either ethernet cables or Wifi. The loss was Powerline ONLY.

The losses occurred even if both the devices were on a single circuit in the same room.

I slowly eliminated every other electrical appliance as possible sources of interference.

I too suspect our SmartMeter. I did some investigation and discovered it communicates with the power company through the power lines. I'm not sure all what gets communicated but our daily power usage is available on a web site.

There didn't seem to be any pattern to it as far as time of day or frequency, just usually once or twice sometime during the day.

Our home has thick wood walls which makes reaching the whole house with Wifi difficult. I ended up with Wifi router and a couple of extenders/repeaters. The thick tongue and groove wood walls and floors make running cables essentially impossible (it's a cabin).

I'm glad I found this thread. It gives me hope that this will be resolved someday. But for the moment I've already wasted way to much time and money on this technology.

Bruce.

 

[DrMopp]

Bruce, thanks for sharing the results of your comprehensive testing. My situation is a little different in that I get not one or two, but many dropouts per day, for a maximum of two minutes, although like yours there is no pattern as to time of day. A little less comprehensive testing than your own has led me to the conclusion that the wiring must be the problem as all other elements have been swapped out at some point (router,cables,pc,adapters) however we don't have a smart meter! Strange that the STB to router adapters (in the same room) have no such problems though.

 

[bachastain]

I had my wiring checked and he found no problem, which is not surprising as this place was built just 5 years ago.

Make sure you're not using surge suppressors and the device is plugged directly in to the wall socket.

Also, check the type of breakers you have. I've read that GFCI (ground fault) breakers can interfere if the signal has to pass though one or more.

I tried every tip I could find and nothing helped my symptoms.

I couldn't think of a way to test my Smart Meter theory so I'm not sure of the real cause. I was able to get the FCC number of the circuit board in the Smart Meter that does the communications with the power company. From what I read on their web site it's supposed to be specifically designed to coexist with other powerline devices.

Bruce.

 

[thiggins]

You have exhausted the simple methods of tracking down the problem. To go further, you're going to need a spectrum analyzer to look in the frequency domain and Wireshark, to see what is actually happening in the data domain.

 

[smagro]

I experienced these drop-outs with several generations of powerline adapter. I think I did not experience it with TP-Link 200Mbps units from many years ago but it's so long I can't be sure. If you go to TP-Link forums it's a very common complaint.

I troubleshot extensively, cables, network cards, software etc. Tried to find a pattern to the dropouts like the central heating coming on or something. I could not.

My eventual cure was to constantly ping my router from the device that was experiencing dropouts (in my case my desktop PC). Just a simple ping 192.168.1.1 -t from the command prompt.

Like shock I suspect it is an issue with Qualcomm chipsets. My fix leads me to suspect the powerline units are waiting for a lull in network activity to do something which results in a momentary network drop. They wait for a lull in activity because they think the drop won't be noticed. Constant pings deny this opportunity.

The 'something' that they are doing, I don't know for sure. Maybe cooling, maybe self-diagnostic. Maybe switching transmission strategy..I am just guessing, I have no idea. But my fix works for me and has had no ill-effects on the units (so far).

 

[DrMopp]

Thanks Tim, but even if I were to obtain a spectrum analyser and Wireshark, (which I have tried before), I doubt the results would mean anything to me! 'Snagro', I will certainly try the ping 'fix'' you suggest. Is it not a little strange that if various manufacturers units suffer from this problem that none of them seem to be able to advise - as you say we are all to a greater or lesser extent 'guessing' but surely the manufacturers would not be. Although having enquired of Netgear support which chipset the XAV5221 adapter uses and been told that they 'do not have that information' I guess I'm expecting too much! Thanks for all your help so far guys.

 

[thiggins]

Thanks Tim, but even if I were to obtain a spectrum analyser and Wireshark, (which I have tried before), I doubt the results would mean anything to me!

I know. What I was trying to say is that getting to the root cause of the problem requires equipment and techniques beyond the reach of normal users.

 

[DrMopp]

Me again! Only just started the 'constant ping' workround so too soon to say if it's working or not - just a thought but does anyone here know which adapters or brands at least that use non-Qualcomm chipsets? As I said earlier I am using Devolo 500's but have had the same problem with Netgear XAV5221's

 

[thiggins]

does anyone here know which adapters or brands at least that use non-Qualcomm chipsets?

http://www.smallnetbuilder.com/tools/finders/powerline/view

 

[DrMopp]

Thanks Tim, although the specific model isn't listed seems like Netgear's models all use the QCA chipset, but no mention of Devolo in the products on the page link you provided, any idea which chipset they use? (Nothing on Devolo Tech datasheet)

 

[thiggins]

Thanks Tim, although the specific model isn't listed seems like Netgear's models all use the QCA chipset, but no mention of Devolo in the products on the page link you provided, any idea which chipset they use? (Nothing on Devolo Tech datasheet)

Sorry, no.

 

[smagro]

You can usually figure out which chipset is used by going to the product website and downloading a firmware update, check the included files.

 

[SansB]

My eventual cure was to constantly ping my router from the device that was experiencing dropouts (in my case my desktop PC). Just a simple ping 192.168.1.1 -t from the command prompt.

I just want to say THANK YOU smagro for this suggestion. Like others in this thread I have been struggling to deal with these intermittent drops since I started using powerline adapters 3 years ago. I actually own three generations of adapters with Qualcomm chipsets (Netgear XAVB5101, Zyxel PLA5205, and Netgear PLP1200). All three of these experience the same intermittent drop out to some degree. I've spent so much time researching and changing things around to try and eliminate the issue, that I had pretty much given up on the technology.

After reading your suggestion, I set up an old laptop to constantly ping Google (I use the Powerline adapters for my WAN connection to centrally locate my Wifi router in my home). The ping has been running constantly for 4 days, and we haven't had a single outage. I've got Asus-Merlin loaded onto my router, so I'm looking at setting up my router to do the ping instead, but this has definitely solved the problem.

It's problems like these that really make me lament how badly supported Powerline adapters are. Something like this could be fixed with a firmware update (if it is indeed a bug with the "power save" feature all of the adapters tout on the box), but it is doubtful at this point even the PLP1200s will see an update. I know Qualcomm pushes out regular firmware updates for the chipsets, but without any support from the device manufacturer there is now way we can get at them.