Upload speed randomly drops from around 20 Mbps to 5 Mbps

[#1]

Hi, my connection speed is usually about 70 Mbps down and 20 Mbps up. Some months ago, there was some kind of local power surge/cut and my Plusnet supplied OR modem died. I had a Google Nest WiFi connected and that was fine, so I got hold of a Draytek Vigor 130 modem and all seemed good. Unfortunately, sometime later I noticed the Google Home app reported the upload speed had dropped to 5 Mbps and other speed tests confirmed this. Rebooting the Google router fixed this.

This has become an ongoing problem, about once a week, sometimes more, sometimes less, the upload drops to the same 5 Mbps and download stays normal. I tried a wired connection, and the result was the same and I've done factory resets, firmware upgrade on the modem and even swapped the Google Nest Wifi for a new one, and still the problem persists.

Could something be happening on my line that is making my router limit uploads to 5 Mbps at random times? All was fine before that power surge/cut incident when I was using the OR modem. I wondered if the Draytek could be the problem but that doesn't need rebooting, just the router.

Thanks in advance for any ideas.

[#2]

Hey @AJK, I'm sorry to hear that you've run into this issue. Have you been able to connect any devices to the router via Ethernet cable to see if the same problem occurs?

[#3]

Hi TheMightyAJ, apologies for my late reply.

Yes, I have tested by connecting directly into the router's ethernet port and get the same results. I'm on here right now because I noticed this morning that the upload speed is stuck at 5.59 Mbps as reported by the Google Nest Wifi app. Google Nest Wifi does a daily speed test which is how I first spotted this problem and confirmed it with other speed test services. The Nest's speed test is internal so not affected by Wifi.

Thanks for getting back to me.

[#4]

Further to my earlier reply, I have now reported this as a fault to get the line checked, the dial tone does seem a bit noisy.

[#5]

Hey @AJK,

Thanks for getting back to us and I'm sorry to hear that there's a bit of noise on the line. We've run a line test on our end and we haven't been able to detect any underlying fault conditions - would you say the noise that you're hearing is constant or intermittent?

[#6]

I think I may have been mistaken regarding the line noise. Our dect phones were noisy but I had tried a little used corded phone which was producing a constant faint high pitched noise. I've just found another corded phone and tried that, and any noise was so faint I'm thinking the other phone was the problem as far as noise goes. Sorry about that.

Anyway, yesterday I had to reboot the router 4 or 5 times because the upload speed kept dropping and sticking to 5.6 Mbps again. I was doing line testing with the phones through the day so thought there was a connection. Today it's fine. Normally I only have to do one reboot during a day and it's fine until the next day or often a few days later. This is the problem, it's so unpredictable but the experience is the same, download unaffected and upload drops to 5.6 Mbps or thereabouts.

I only have the Hub 1 as a spare option for testing, but if I leave that on then it won't reach my office and I might have to wait a week to confirm anything. It won't work with my Google Nest Wifi to give me the mesh to reach my office, so I think I'd need the Hub 2 for that kind of set up.

I have the openreach mk2 socket, I don't suppose anything could be wrong there that could be causing such issues?

[#7]

Hey @AJK,

Thanks for getting back to us and I'm sorry to hear that the initial line of testing didn't get to the bottom of the issue. I've had another look over things today and I can see that the connection seems to have stabilized over the last 2 days - did you change anything regarding the setup since you posted this update on the thread?

[#8]

Hi @TheMightyAJ I didn't change anything, and it's been performing fine with normal speeds until this morning with the upload again stuck at 5 Mbps. I'm leaving it for as long as I can so you can hopefully confirm it. I've made no changes day to day, nothing plugged in, unplugged, or even touched.

[#9]

Hey @AJK,

I've run a test on the line this morning and from what we can see, the Upstream Sync Speed is currently recorded at 20Mbps. If you run a wired speed test, does this still come back as 5Mbps on your end?

[#10]

Hi @TheMightyAJ 

Before moving my computer to the room with the router in I did some more testing. After your reply, I retested, and the Nest router's internal speed test reported normal upload speeds again, but further tests now show it back down to 5 Mbps. This is consistent with speed test sites like speedtest.net over full strength WiFi. The Google test is internal so would be the same as a wired connection, which I have confirmed previously.

[#11]

Thanks for confirming that. Since the speed's not dropping below a minimum guaranteed rate and the tests we've run have come back as we would expect, with no drops in the last few days, there's not much room left for us to support this particular query I'm afraid. The speed will fluctuate from time to time and we can't outright prevent that from occurring, especially over Wi-Fi or when additional equipment is setup on the network. 

My best advice would be to connect via Ethernet cable wherever possible and if the problem continues to occur, please make a note of when it happens plus any other events that coincide with it. This might help to narrow down a cause, which we could potentially then use to implement a solution around it.

[#12]

Thanks, but connecting via ethernet makes no difference, but rebooting the router solves the problem. All the time the modem stays connected and rebooting that makes no difference. My only other non-expert thought is that the modem is sensitive to something on the line that comes and goes, and the router gets locked to a 5Mbps upload.

I'll either have to plug in my old Hub1 and try to get everything working with that for long enough to test with its modem. Or I could order a Hub 2 and just pay postage I suppose? That would enable me to hopefully disable its Wifi and use the Nest Wifi instead while I see how that goes with its modem and if need be, see how things go with and without its Wifi router features.

Just rebooted router and full speed is back 72 down and 20 up.

Frustrated from Worcester.

[#13]

We could certainly look at providing a Hub 2 if that's something you'd like to try. Might be worth trying with the Hub 1 first as you say though.

[#14]

Thanks @TheMightyAJ 

There's something about Wednesdays.

I'm trying to find a good time to switch over to my old Hub One so I can leave it on for long enough to test but looking at my current router's speed tests this morning I noticed that for the last three Wednesdays the upload speed got stuck to 5.6 Mbps.

I've attached a screenshot to show the last three weeks from today.

Nothing changes here on a Wednesday so any ideas?

Andy

[#15]

Thanks for getting back to us Andy and that's quite interesting. It's a longshot, but are there any events that take place on Wednesdays in your local area?  Like, regular maintenance work for example?