PowerLine (mains networking) adapter issues

mikeymikec

Lifer
May 19, 2011
17,708
9,574
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I've been using powerline adapters to supply networking throughout my house for a couple of years now, and until very recently it's worked pretty much perfectly: Maybe once a year I'd need to power-cycle one for 30 seconds, but pretty plain sailing and pretty much perfect throughput onto the Internet (speedtest.net).

Admittedly lately I've been thinking that my computer seemed a little slow in connecting to websites (like the response times were a little off), but today I can't remember what made me start to check, but a speedtest.net run basically got me about 10% of what my Internet connection is capable of (Internet connection is normally about 55-70Mbps down / 15Mbps up). My mains networking adapter had a red light on it for poor signal quality. I started by swapping it out for a spare. No difference.

As it's always been plugged into an 8-way with surge protection (not ideal I know, but it's always worked), I tried plugging it into the wall socket next to the 8-way. Still crap throughput mostly, though sometimes I might get 50% of the normal connection speed. I tried other PCs connected to the homeplug network through different adapters, and they seemed to be consistently getting 75-100% of the total capability of the connection, while sometimes my PC would get readings of ~1Mbit down. Another brand-new PC that's connected to the same network switch and then homeplug adapter has been getting similar-ish readings, but in general pretty erratic. Often the upload speed would be significantly higher than the download speed.

I've also tried power-cycling the adapter nearest the router, though evidently it's supplying the other two mains networking adapters without issue. My only other thoughts are to power cycle the lot of them or to disconnect the 8-way in my room in case that has some kind of issue (though as my room's network switch - which I've also bypassed is supplied by it I'll need to clamber around a bit to achieve that).

I've wondered whether another appliance in the house is causing problems. The only new one I can think of is a water fountain for the cats that my wife plugged in today, but I unplugged that early on in testing as a precaution.

Thoughts?
 

SamirD

Golden Member
Jun 12, 2019
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www.huntsvillecarscene.com
I've run into similar patterns like this on my netgear 500va nanos that I've had for years. It turned out that the one powerline I had connected to ethernet was starting to have packet loss through that ethernet port, so I changed it to another ethernet port in another part of the house. Then I noticed still general slowness and moved it to other ethernet ports around the house until it was closer to the one I saw speed issues on, and that fixed the problem with that node, and other nodes lost their connection and speed. :(

But since the bandwidth at the other nodes still gets the job done, I've left it be. My only guesses were that as the wires and the units have aged, some subtle things have changed that has made the speeds slower. I think the same could be said for your case, although any change in load on the electrical system could affect something (as is in my case too).

Moca was the solution to all this until I found out that the &^$%&^% contractors just dumped the cable into the crawl space without running it to the demarc. Mother$%$#$%sss!!

One way to test just the powerline adapters themselves is to test them both connected to a power strip or single duplex outlet and see how they fare. If they're acting funny in that scenario, I think you may have a unit going out.
 

mikeymikec

Lifer
May 19, 2011
17,708
9,574
136
Since that day, the throughput more or less returned to normal (earlier today I was getting throughput of 40Mbits/sec, which is pretty much fine by me). Then I plugged a laptop into the same 8-way as the powerline adapter, then the network throughput tanked.

On the day this first happened, I plugged in a different laptop (with a different charger).

Coincidence? I thought it reasonable that it might be the 8-way malfunctioning so I stripped it out and stuck a plain and simple 4-way in. At least the connection is stable now, but the speed hasn't returned (yet?).

Admittedly I guessed this possibility the last time around and unplugged the laptop, which I haven't yet done this time. I'm not sure why there apparently would be a recovery time for the throughput, though this time around I haven't power cycled all the adapters yet.
 

SamirD

Golden Member
Jun 12, 2019
1,489
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www.huntsvillecarscene.com
I've run across something similar, but what I did was plug in a surge strip in the same outlet (lower one) as the powerline and then something behind the surge strip (which filters the noise) and has some better results.

I do think the issue could be somewhat related to that laptop power supply (especially if it is a compatible and not an original oem unit), but I would first test the units in the same outlet to see if anything is wrong with the units.

Then I would proceed to test in your use scenario. Because if you identify some flaky units in the first test, you've found the root cause.
 

Muadib

Lifer
May 30, 2000
17,916
838
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I always had trouble when plugging my powerlines into a surge protector. When they are plugged directly into an outlet, no issues. I have my main unit in a extension cord now, and it's still all good.
 
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