[SOLVED] Upload speeds extremely slow during late night, but download speeds are fine. Is it throttling by my ISP ?

[Himaster]

For the last few weeks, my upload speeds have slowed down to less than 1 Mbps at night (best estimate is around 10pm - 8am), while during the day they are around 50 Mbps. My download speeds remain around 500 Mbps at all times of the day (I am on a 500/50 Mbps plan with WoW). When the issue first arose, I was still using my ISP's modem and router, but around a week ago I switched to my own modem and router and the issue has remained. Further, I've tested plugging the modem directly into different PCs and obtained the same results, as well as on different devices on WiFi when plugging the modem into my router. The coax inside and outside my home was also laid only a year and a half ago, and there are no splitters (just a direct line from the outside to my modem).

I don't think it could be a congestion issue since I assume that late night usage is lower, and there's nothing different about our usage during the night as opposed to the day (and the issue was the same when just using the modem with one PC). I also don't think it could be the coax since the issue only happens at certain times. Further, I don't think it could be my equipment since the issue was the same with my previous equipment, and my current equipment is brand new. It's also not device or protocol specific, since it happens on all devices, both wired and wireless.

The only thing I can think of is that my ISP is doing something weird on their end. I was thinking it might be throttling, but testing my speeds with a VPN showed no difference, and I don't understand why they would want to throttle late at night (and only my upload speed). Could it be some weeks-long maintenance they are performing at night that only affects uploading? It seems unlikely to me, but I can't think of anything else.

For the record, I am using a Motorola MB7621 modem and a Synology RT2600ac router, and my internet is provided by cable. There are currently ten devices on my network, although only a couple of them ever get any significant use. If you need any more information than this please let me know and I will try to provide it.

I really appreciate any help at all, regardless of whether it solves the issue.

 

[bill001g]

Time of day problem are almost always other people causing it.

So you said you plugged directly into the modem and it had the problem ? Since you can only plug 1 device into the modem this would eliminate the possibility that it was one of your other machines doing backup or something. Although I doubt it check that the machine you used to test is not doing something in the background. You should be able to see the total network usage on the network tab of the resource monitor.

After this you have pretty much eliminated all the stuff inside your house that can cause this. Problems with wires or the modem would happen at all times not just at night.

That is somewhat strange time to have issues. Most time you see people complain it is 5pm to 10pm when people are getting home from work and everyone is starting up netflix or other stuff.

I would doubt the ISP was limiting you especially at those times when internet usage is very low.

Although you share the bandwidth with your neighbors the total shared is likely above the 50mbps they sell 1 family. You would need multiple neighbors using all their upload bandwidth to exceed the ISP capacity. Then again it only takes a couple idiot teens running torrent to impact a cable segment.

This has to be a ISP problem but I am unsure how you are going to get them to fix it. Do they have support that you can call during those times. You can show them the speed test results. Make sure you are plugged directly into the modem again when you call so they don't blame router/wifi/other machines etc etc. Since you are not getting the contracted rate you would hope they will look at it. If they do not have support during those times you are going to have to be a pest until you get a tech that will work with you. Most will run their little script and say they see no problem and try to close the call.

 

[Himaster]

Time of day problem are almost always other people causing it.

So you said you plugged directly into the modem and it had the problem ? Since you can only plug 1 device into the modem this would eliminate the possibility that it was one of your other machines doing backup or something. Although I doubt it check that the machine you used to test is not doing something in the background. You should be able to see the total network usage on the network tab of the resource monitor.

After this you have pretty much eliminated all the stuff inside your house that can cause this. Problems with wires or the modem would happen at all times not just at night.

That is somewhat strange time to have issues. Most time you see people complain it is 5pm to 10pm when people are getting home from work and everyone is starting up netflix or other stuff.

I would doubt the ISP was limiting you especially at those times when internet usage is very low.

Although you share the bandwidth with your neighbors the total shared is likely above the 50mbps they sell 1 family. You would need multiple neighbors using all their upload bandwidth to exceed the ISP capacity. Then again it only takes a couple idiot teens running torrent to impact a cable segment.

This has to be a ISP problem but I am unsure how you are going to get them to fix it. Do they have support that you can call during those times. You can show them the speed test results. Make sure you are plugged directly into the modem again when you call so they don't blame router/wifi/other machines etc etc. Since you are not getting the contracted rate you would hope they will look at it. If they do not have support during those times you are going to have to be a pest until you get a tech that will work with you. Most will run their little script and say they see no problem and try to close the call.

Yeah the time of day in particular is why I am so confused. I can't imagine it's a congestion issue since usage should be very low during the hours it occurs. I did plug my desktop into the modem and had the same issue (and tried it on my laptop to confirm it wasn't related to that particular desktop). And I agree that it wouldn't make sense for them to be throttling me at these times.

Do you think it could be related to some maintenance they're performing (I have no idea if they are)? Otherwise I just don't know what it could be. I guess my best bet will be to just keep pestering them to look at it, although if they send a technician during the day they probably aren't going to see anything. They do have customer support 24/7, so I should be able to talk to them while the issue is occurring, but I'm sure as you said they're going to try and say everything is fine on their end.