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Question Poor PLC speeds

elijah_

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Hi,
I live in a house with three floors and because there was no space to fit another cable for internet through the walls, the PC in my office (2nd floor) is connected to the modem (ground floor) via PLC. This has been working mostly fine for years now, but last week there were three days where I got really poor speeds. From friday it was all back to normal again (20 Mbps) until today where it drops to new lows of around 150 Kbps and peaks at 2.3 Mbps.

There's really nothing different from new devices using power in the house, so I'm wondering what may cause such a drastic difference? Could it be old powerlines, more power being used in the neighbourhood? Is there any ways for me to figure this out? Last week I tested the PLC on the first floor and got upwards of 15 Mbps so it seemed like there was some issue with the connection to the second floor, but since it was all back to normal for several days I'm not so sure.
 
It is not power usage. If the units could run on say battery you would not even need electricity in the wires. They are purely using the wires as antenna they kinda work like wifi but use wires instead of air to transmit data.

In general nothing outside your house can affect powerline. The signal can not pass though the new fancy digital power meters and even if it does it can not pass though the transformer on the street. This is why poweline is so much more stable than wifi for most people.

The most common problem with power line is some source of interference inside your house. It can be anywhere since all the wires are connected. In most cases it is something with a motor but I have seen people post here that the fans in power supplies can do this also. I have a shopvac that instantly kills powerline no matter where I plug it in.

These tend to be tricky to locate. You could try to turn off devices in your house to find it. Brute force method of turning off circuit breakers to areas of the house tends to cut things down quickly and much easier than say unplugging the refrigerator or garage opener.
 

Ralston18

Titan
Moderator
And I will ask about weather - any correlation with rain, temperature, wind...?

Most buildings move, twist, expand and contract with weather.

If there is an electrical cable or connection somewhere being stretched (contraction), loosened (expansion), or twisted in some manner then the problem would indeed be intermittent.

Indeed tricky to locate but any weather related correlation may help narrow things down.

Could simply be a poor connection in an outside porch light that impacts the entire circuit.

Maybe when the sun is directly on it. :)
 

elijah_

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And I will ask about weather - any correlation with rain, temperature, wind...?

Most buildings move, twist, expand and contract with weather.

If there is an electrical cable or connection somewhere being stretched (contraction), loosened (expansion), or twisted in some manner then the problem would indeed be intermittent.

Indeed tricky to locate but any weather related correlation may help narrow things down.

Could simply be a poor connection in an outside porch light that impacts the entire circuit.

Maybe when the sun is directly on it. :)
No patterns there. Was relatively warm last week when this issue first came up as well as when it stopped on friday. It's been colder since saturday (sometimes cloudy, sometimes sunny) when the speeds were still fine and now today the internet is the worst it's ever been all of a sudden and the weather's the same as yesterday.
 

elijah_

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It is not power usage. If the units could run on say battery you would not even need electricity in the wires. They are purely using the wires as antenna they kinda work like wifi but use wires instead of air to transmit data.

In general nothing outside your house can affect powerline. The signal can not pass though the new fancy digital power meters and even if it does it can not pass though the transformer on the street. This is why poweline is so much more stable than wifi for most people.

The most common problem with power line is some source of interference inside your house. It can be anywhere since all the wires are connected. In most cases it is something with a motor but I have seen people post here that the fans in power supplies can do this also. I have a shopvac that instantly kills powerline no matter where I plug it in.

These tend to be tricky to locate. You could try to turn off devices in your house to find it. Brute force method of turning off circuit breakers to areas of the house tends to cut things down quickly and much easier than say unplugging the refrigerator or garage opener.
I couldn't come up with anything there unfortunately. I've spoken to everyone in the house and the only new device is an amazon fire stick, which was both plugged in and out, both when the internet was bad and good. I can still play around with the circuit breakers, though I find it strange that there was never a problem for years until last week where 3 days were bad, then back to normal and now terrible again with seemingly nothing having changed inside the house.
 

elijah_

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Back to brute force then per @bill001g

Narrow to some circuit, then maybe a certain device.

Maybe a specific outlet or switch in that circuit serving that device.

You may need to get an electrician to check continuity and inspect switches and outlets.
Will do, thanks! If I do find a culprit device, would I immediately notice an effect or could it take time for the speeds to go up?
 

elijah_

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Another thing I noticed - the PLC adapter in the office is red (bad connection), while in one of the other rooms on this floor another adapter is orange (indicating medium connection quality and offering WiFi up to 11 Mbps). I can't really unplug anything right now, but could this be an indicator that something between these two sockets is the problem?
 

Ralston18

Titan
Moderator
Certainly an indicator but not much more than basically being a "Check Engine" light.

The PLC's User Guide/Manual and/or the manufacturer's website may offer some additional insight as to specific problems.

If you can establish, some temporary "circuits" using other electrical paths and outlets via relocations, extension cords etc. to get a "green light" status that would likely help narrow down the problem.

Problem is that extension cords etc. may be just as bad as the original host circuit.

Worth a try as I understand it all. Who knows what might be discovered.

There may be other ideas and suggestions. No problem with that on my end.
 

elijah_

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Certainly an indicator but not much more than basically being a "Check Engine" light.

The PLC's User Guide/Manual and/or the manufacturer's website may offer some additional insight as to specific problems.

If you can establish, some temporary "circuits" using other electrical paths and outlets via relocations, extension cords etc. to get a "green light" status that would likely help narrow down the problem.

Problem is that extension cords etc. may be just as bad as the original host circuit.

Worth a try as I understand it all. Who knows what might be discovered.

There may be other ideas and suggestions. No problem with that on my end.
I reckon I found it - problem appears to be my housemates work notebook. After unplugging it, the speeds in my office go from currently around 8 Mbps to 18. Not using it is obviously not really an option, moving it from the power strip to another socket didn't help - is there anything else worth trying?
 

Ralston18

Titan
Moderator
How is your roommate's notebook connecting: wired or wireless?

Very good chance either way that there is some network related misconfiguration. Maybe a duplicate IP.

Especially if he is going back and forth between home and work networks.

Here are a couple of things you can do:

1) Run "ipconfig /all" (without quotes) on both computers via the Command Prompt

2) Run "arp -a" as well. First a few times without the work notebook connected then with the work notebook connected.

What you are looking for are any duplicated IP addresses. I.e., the same IP address showing up on any network devices. Devices can be identified via their MACs.

Who has full admin rights to the home Router? There may be some information in the router's logs if logs are available and enabled.

There may also be some configuration options to correct the problem.

But we do need to identify the problem first.
 
Reactions: Mandark

elijah_

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How is your roommate's notebook connecting: wired or wireless?
It's using WiFi but the problem was the power/charger. Like I had problems on my end even when the notebook was closed and plugged in, but as soon as we unplugged the charger from the power outlet the internet speeds in my office went from 2-8 Mbps to 18-20 Mbps.

Is the rest of your comment still relevant in that case? The speeds I got fluctuated a fair bit but I'm not sure the internet use of that notebook played any role there.
 

Ralston18

Titan
Moderator
Is the rest of my comment relevant? At this time - most likely not.

If the network continues to function at 18-20 Mbps then apply the "if it is not broke, do not fix it" rule.

"Ipconfig /all" and "arp -a" are for diagnostic use.

You might run both commands on both computers just so you can gain a sense of the information provided.

Then simply keep that all in mind if some other issue appears.
 
In general electrical equipment is not suppose to transmit signals that would interfere with other equipment. All equipment puts out some radio signals on various frequencies it just depends whats allowed by law and if they are exceeding the limits.

Going to be hard to say if the charger is defective and exceeding some limit or if your power line units are just very susceptible to this particular brand of charger but it is withing the legal limits.

Some tricks you can try would be to plug the charger into a extension cord. Sometimes this helps...not exactly sure why though. You could also try a power strip with a surge protector.
 

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