Vasili's Blog

powerline

This time it's not quite related to the homelab setup itself, but my home networking.

Original Setup

We live in an older townhouse, which was never wired for any kind of ethernet, so it's all WiFi for us, and WiFi is quite crappy usually. Very high speed variation, packet loss, latency, neighbours microwaving knocks out your multiplayer game... You know the drill.

The way the current set up is wired is pretty precarious too.

We have a fiber line coming in the basement, and you don't want to put your wifi router in the basement of a 3-story townhouse. But this is new system by Telus, where the router is essentially hard-wired and does not have a WiFi, but instead you have another unit which does WiFi. And you can connect it to the Fiber router either via MoCA (over antenna coax) or over 10Gbps ethernet.

When ours was installed, we probed some antenna cables and found one that terminates in the living room on the second floor, and the TV happens to reside there, so we thought – it's as central of a location for a wifi router as we can have, that also kinda fits aesthetically. My wife wouldn't want to have just some random-ass router just standing on the floor in the middle of the house, just because the antenna cable happens to terminate there.

My office however is on the third floor on the opposite end of the building, relative to the router. I'm not directly above it.

flowchart LR

    subgraph Second Floor
        WiFi
        WiFi --Ethernet--> Homelab
    end

    subgraph Basement
        Fiber --> Router
        Router --> PowerlineA
    end

    Router -.MoCa.-> WiFi

    PowerlineA -.Mains.-> PowerlineB

    subgraph Third Floor
        PowerlineB
        Laptop
        PC
        PowerlineB --Ethernet--> Laptop
        PowerlineB --Ethernet--> PC
    end

    WiFi --> Phones

Issues with this setup

It was like I described above, and I would suffer horrible packet loss that made zoom calls basically impossible. You'd get disconnected, robot voices, all the good stuff... I even installed a program to continuously ping my router so I can be warned when it started to crap out. This was no way to live and work, but we are still somewhat far from a renovation big enough to open up walls and floors to lay CAT6 cable and build networking closets...

I've looked at MoCA adapters, but for some reason they are really expensive. Like $200-$300 for a pair. Then I looked into alternatives and found the TPLink Powerline adapter (TL-PA9020P), which was available from a local computer shop, open box for $100, which was quite a bargain.

I bought it, brought it home, and hooked it up. One unit went in the basement on the same wall socket the router was connected to, and the second went all the way up to my office. Both units have 2 ethernet ports and I believe they use hubs internally (more on that later). They were linked up, all the lights were glowing red and the traffic was flowing.

I was getting about 100Mbps over powerline and about 70Mbps over wifi, with no packet loss and no crazy latency spikes. So it was a win.

Where I am now

I've been using this set-up for months, without really thinking about it. But getting the mini-pc and starting to migrate some services from my main PC that is in my office, I though, am I getting the best speeds here? Why do I only see 100Mbps. Apparently that number was quite a red herring. I started googling, and some people suggested that my ethernet cable on either end is to blame, since it tops out at 100Base-T. So today I've unpacked some CAT6 cables rated for 10000Base-T and plugged them in.

No change. I started scratching my head... If I plugged in the laptop directly into the router or the MoCA Wifi Box I'd get ~800Mbps. If I was line of sight to the router over WiFi I would get ~600-700Mbps. So clearly the powerline thing does not deliver. It is rated for a gigabit.

The hunt for the perfect wall socket

Okay, let's see, does moving one of the adapters change the situation? I unplug it and go to the guest room on the same floor... Suddenly I'm only reading 75Mbps. I go one floor down – 150Mbps. Finding a socket in the basement gets me as high as 200Mbps.

Eventually I even tried having both adapters on the same cable run, which should be as close to ideal conditions as you can get. 300Mbps and no more...

I'm not sure what kind of environment one must have to get it to a Gigabit. Maybe over 10cm 99.9% pure copper gold plated cables or something, running on a pure sine from a generator.

Another problem is that every floor is connected over a separate main cable. They all terminate at the breaker. Even if I try to have one adapter on the first floor hooked up to the MoCA Wifi Box the signal has to go to the basement, through the breaker, through the main bar, and out another breaker to the run that goes to the third floor. Ironically the basement socket is the best possible placement for one of these adapters, as that has the shortest run to the breaker box.

Conclusion

I guess my power lines are way too noisy, and that makes powerline only 10% efficient. Now that I do record and edit youtube videos it would be nice to get those 800Mbps upload speeds that our symmetrical fiber provides. So maybe I should revisit the MoCA adapter idea. Time is money after all.

#homelab #networking #powerline #10000baseT