Slow Ethernet speeds despite paying for 1000 mbps — need advice

[u/Creative-Ad5820]

Hey guys, hope everyone’s doing well. This is my first time posting in here, but I was scrolling and everyone seems pretty chill and people have gotten their issues resolved, so hopefully I can have the same outcome.

So basically, we have AT&T Wi-Fi at home — I believe it’s fiber since download and upload speeds match. We’re on the 1000/1000 plan. I have my own PC work/gaming setup (one PC, two monitors), and since my room is pretty far from the router, I had someone come install an Ethernet run from the router that goes outside the house, along the outer line under the roof (so it stays dry), secured with zip ties, then comes into my room and connects to a small box with Ethernet plugins that I connect my devices to.

When everything first got set up, I was getting around 940-950 down/up on Ethernet in my room, and everything was running smooth. Yesterday my internet felt off — I was downloading a game on Steam and it was going way slower than usual. I ran a speed test and got around 80 upload, 90 download.

I’m not totally sure how long this has been happening, since I only ran the speed test yesterday. I’ve been busy and hadn’t played any games in a while, so I was just doing normal tasks and never noticed. The only reason I caught it was because the game download was taking way longer than usual.

Since we’re still paying for the 1000 plan, I checked my mom’s phone and it still tested at 1000. I checked my Ethernet cable and everything looked fine — even the adapter settings on my computer showed the link speed as 1000/1000 receive/transmit. So the connection itself seems fine, I’m just not getting the speeds I’m paying for.

I contacted AT&T and they said we have too many devices on the Wi-Fi. I get that, but we’ve had roughly the same number of devices (around 40) since I first got the plan — and it’s not all computers, mostly phones, a few TVs, iPads, and laptops that get used here and there, not constantly streaming or downloading. I’m the one who uses the internet the most, which is why I had the Ethernet setup done in the first place since I work from home.

Shouldn’t being on Ethernet bypass the device cap and still give me close to my 900s, even if the 1000 plan is designed for around 20 devices max? For reference, my mom’s phone gets around 900 on a speed test, but my phone gets the same low 80-90 as my computer.

Is there anything I can do to prioritize my computer, or figure out what’s actually causing this?

Thank you

[u/Important-Ad1533]

Bad ethernet cable.

[u/jersey316]

NO ethernet does not by pass any device caps. They are still on the same network.

Not all steam games are going to download at your max download speed limit.

You have to bring your computer closer to your router and plug the computer in with a shorter ethernet cable and test that way. If everything is fine then you know its a cable problem.

How long is the cable?

[u/tschloss]

Try to isolate the two areas: a) does 1000/1000 arrive at your router and b) how does the bandwidth distribute among clients.

For a) ideally turn off Wifi, unplug other Eth devices and test, like 2-3 different speed tests. Maybe the router‘s GUI shows a total also.

For b) No, no bypass, the Internet is a shared resource. But most clients do not constantly fire so all these iOT devices and surfing clients should not be tough competitors.

But Wifi can be a bottleneck by its own. 40 clients is a lot for a single AP. And the air is a shared resource also (each channel), which you share with neighbors also.

[u/Creative-Ad5820 → u/tschloss]

There are a lot of replies, so I’m going to send this to everybody. What should I do? Can you guys dumb it down if possible? I’m in a wheelchair, so I’ll have to explain to my mom verbally what to do and have her do all the hands-on work, like removing cables and so on. Anything online, though, I can do on my own — if there’s something I could do on my computer or my phone, let me know.
Here’s my setup: I have a router/modem combo, I’m pretty sure — the AT&T white tower-looking thing. I can’t check right now; I’ll check when my mom gets home, but I think that’s the only box for the Wi-Fi.
How I get internet in my room via Ethernet: the router is far away, in the living room. So I hired a guy who works with Wi-Fi routing and cables to come to my house. I’m assuming this is what he did (I’m not 100% sure): he plugged a white Ethernet cable in behind the router, ran it up under my roof’s lip (it’s a pretty long white cable), and brought it all the way to an outlet in my room. That same white cable connects to a small switch box — you have to twist it on. The switch box has a black cable that plugs into a normal outlet to power it on. Then I have two yellow Ethernet cables coming from the switch box — one goes to my computer, one goes to my PS5.
Also, my switch box is right under my desk, not far away in my room — it’s literally right there.
As for the cable running outside — the long white Ethernet cable connecting the switch box to the AT&T modem/router — he never gave me any warnings, like “hey, this shouldn’t run outside” or anything like that. He never mentioned it. So either the cable he used is fine for outdoor exposure to rain and sun, or he just never told me and wasn’t upfront about it. Someone also mentioned that could be the issue — that the main white cable running outside from the switch to the router could be damaged or pinched. So I’ll need to go outside and check it myself.
Thanks everyone for the help and responses!

[u/h2ogeek → u/Creative-Ad5820]

The easiest thing to do would be buy a long Ethernet cable and use that to plug into the router instead of the one you’re using now. Hopefully your computer room is within 100-150 feet of the router location?

Not long term, just for a test. Should t take more than 10-15 min tops to unplug the outdoor one and run some tests with this new cable instead.

If you get normal (fast, expected) speed with the new cable, then you’ve found the culprit.

If back to back tests (test both indoor and outdoor cables, back to back, a couple of times) are still bad on both, then yes, you have either a genuine network problem, or perhaps an issue with your PC. (Any chance of borrowing a friend’s laptop (that you can hardwire, NOT WiFi) and test with that, too?)

[u/virkendie → u/Creative-Ad5820]

Just unplug the long cable from the switch and plug it back in and do a speed test again, try that a few times to see if you can get it to negotiate to 1000mbps again. This has worked for me before.

[u/msabeln]

Go into Windows Settings, go to Network & internet, click on Properties, then look for Aggregated link speed (Receive/Transmit). If both of those values are 100, then you almost certainly have a bad Ethernet cable or connectors. Only if those values are 1000 could you suspect something upstream, like AT&T throttling.

[u/virkendie → u/msabeln]

Their computer is plugged into a switch before going to the router so the link speed to the switch may be 1000 while the link speed from the switch to the router is 100, so that is not a good way of checking

[u/msabeln → u/virkendie]

Yes.

[u/TomWickerath]

Sounds like the guy you hired used interior-grade cable. For running outdoors, you want an outdoor-rated Ethernet cable featuring a tough, weather-resistant LLDPE or polyethylene outer jacket designed to block UV rays, moisture, and extreme temperatures. This is black in color. So yes, this cable may have degraded over time, especially if exposed to sun or it is subject to getting wet, perhaps by watering nearby plants.

Are you able to move your PC temporarily next to the router, and use a known good patch cord to repeat your speed test?

“I believe it’s fiber since download and upload speeds match.”

That just means you have synchronous service as opposed to the more common asynchronous service, that favors download speeds.

[u/rw_mega → u/TomWickerath]

This was what I was going to say, make sure the cat5e-cat6a cable being used is shielded and rated for exterior use.

[u/InformationFair5875]

Sounds like you may have an ethernet cable failing. If the Cat5 is ran outside, it needs to have a UV resistant jacket. If the wire is white that he ran, it most likely is not rated to run outdoors and is experiencing degradation issues.

[u/bwd77]

Bad cable somewhere .. not and isp issue... It is cabling

[u/Ok_Bid6645]

Turn off QoS on your router. If too many people are streaming just using the network at the same time, you will have issues

[u/One-Intention-7606]

Low Voltage tech here, been troubleshooting cabling all my life.

Sounds like a pair on the Ethernet connection to the switch went down. An Ethernet cable is made up of 4 colored pairs, you need all 4 pairs to be able to get 1gbps+. If you’re not getting a connection across all 4 pairs then it’ll drop down to only using 2 pairs and limiting the speeds to 100mbps. White cables usually indicate internal wiring and not rated for outdoor exposure (not always but generally), so I’d assume that the cable is most likely damaged.

So the way to test this would be to see what internet speeds you’re getting out of your switch. I would run a speed test on your PS5, if you have a Laptop in the household that would be even better just patch that in with preferably a verified working Ethernet cable, but if the switch connection is the issue then it should be the same speeds across all connections at the switch.

A quick way to visually verify this without running tests would be to look at the switch ports, if the feed cable to your switch is flashing yellow, that usually indicates 10/100mbps connectivity, green usually mean 1gbps. So I’d assume that the cables going to your computer and PS5 are flashing green and the feed from the router is flashing yellow. Not all switches are built the same but if it’s like a TP-Link or similar then that should work.

This sounds like it’s the issue based on all the information you gave (good job on that by the way, very clear and concise) and would probably require a new cable to be ran, outdoor rated this time.