Home Network loses internet access when downloading

[Andryu]

Hello,

I have recently updated my home network. In the image bellow you can see how it is set up.
The 3 cat 6a cables all have at one point a lot of strain (possible cable damage?).

Here is my issue:
On my PC when I m downloading at full speed, the router will lose internet access after about 10-60min.
The router lights are normal, I can connect to the router management page (192.168.x.x) normaly.
Also tried to connect to the router directly  to make sure it doesn't have internet, it didn't.
If I restart the router then the internet is back to normal.

I also tried replicating the issue by connecting my PC directly to the router and tried downloading, there was no issue this way it never lost internet acces. (EDIT: via a different temporary cable)

I would like some help determining the cause of this so I can fix it, I don't want to fix probable causes, that are hard to fix like changing cables, and end up having the same issue.
PS I don't have proper tools but I can buy something if needed.

Router: ZTE ZXHN H108N
- Hardware Version: V1.2
- Software Version: V2.5.5_VDFT13
- Boot Loader Version: V1.2.0
- DSL Firmware Version: 4926e811

Switch: Mercusys MS105G Unmanaged L2 Switch

WiFi: Xiaomi AX3000

Motherboard: P8P67pro REV 3.1
- Lan Controller: Realtek RTL8111E

Service Provider: ADSL-24
- Actual Speed: 13Down, 0.85up, 30ms

[icecream-guy]

did you see topic here?

https://www.networking-forums.com/home-and-small-office-networking/internet-connection-randomly-stops/

[Andryu]

I haven't tried restarting the computer but I m confident it won't change anything since I tried connecting to the router directly with other devices too and there was not internet. But I will try it just in case once I get home.

EDIT:

Restarting the computer did not change anyhting

[deanwebb]

When you lose Internet, does connecting directly to the router restore Internet? If yes, then the unmanaged switch is likely the issue.

[Dieselboy]

OP, icecreamguy posted a link to another thread where there is a fair amount of troubleshooting explanation there. It will help you.

Though if you want my best-guess then I would put $10 on the ADSL dropping during the download and having issues retraining to the DSL. Often, ISPs want to "show off" and give their customers the absolute fastest speed internet that they can at the cost of stability and reliability. My bet is that, during the download which slams the line, the modem is losing sync with the line frequency. This then causes the DSL interface to restart and a flashing light should indicate this on the modem. Once it has retrained, the flashing light should remain solid and depending on how your ISP provisions your service will depend on what your modem does next. Usually, the modem will login to the ISP and obtain an IP address from the ISP.

If you have a noisy line, there could be interference causing an issue. You can often listen to this noise on ADSL lines by plugging in an analog telephone. Dial a single number so that the telco stops playing dial tone. You shouldnt be able to hear anything really but any hissing is noise. This is why the ISPs often reply to ADSL internet issues by asking "is the modem plugged into the master socket" as often the master socket in the home is extended internally and wiring gets knocked by vacuum cleaners etc or are just installed poorly.

The other bet I would hedge for $5 would be that the modem is not that great spec, has low CPU and memory resources or software bug and the whole device is either locking up or crashing, forcing a reboot. This will cause added down time because the modem takes time to restart and load the software and only after a completed boot will the DSL line go through the sync process and subsequently log into the internet line.

If you are fine to keep a wired connection, then it will help rule out wifi drops also. I suggest to check the link on the first reply because it (hopefully) will guide you through some easy troubleshooting steps that will usually confirm where the issue is. 

[Andryu]

When you lose Internet, does connecting directly to the router restore Internet? If yes, then the unmanaged switch is likely the issue.

As I mention in my post no it doesn't. The only way to restore the internet access is by restarting the modem/router. Though I think once it got restored by itself after some time, not sure if I can replicate that.

OP, icecreamguy posted a link to another thread where there is a fair amount of troubleshooting explanation there. It will help you.

The only thing I could find there was some things about pinging and IPs, not sure if it will help me but if you think it will help with identifing the issue then I will try it out.

Though if you want my best-guess then I would put $10 on the ADSL dropping during the download and having issues retraining to the DSL. Often, ISPs want to "show off" and give their customers the absolute fastest speed internet that they can at the cost of stability and reliability. My bet is that, during the download which slams the line, the modem is losing sync with the line frequency. This then causes the DSL interface to restart and a flashing light should indicate this on the modem. Once it has retrained, the flashing light should remain solid and depending on how your ISP provisions your service will depend on what your modem does next. Usually, the modem will login to the ISP and obtain an IP address from the ISP.

If you have a noisy line, there could be interference causing an issue. You can often listen to this noise on ADSL lines by plugging in an analog telephone. Dial a single number so that the telco stops playing dial tone. You shouldnt be able to hear anything really but any hissing is noise. This is why the ISPs often reply to ADSL internet issues by asking "is the modem plugged into the master socket" as often the master socket in the home is extended internally and wiring gets knocked by vacuum cleaners etc or are just installed poorly.

I don't think this is the issue because I have never had this same problem in the past and I've been using this modem for years on the same connection. It is true though that my line has had issues in past and it's a shity one but I never had this particular issue.

The other bet I would hedge for $5 would be that the modem is not that great spec, has low CPU and memory resources or software bug and the whole device is either locking up or crashing, forcing a reboot. This will cause added down time because the modem takes time to restart and load the software and only after a completed boot will the DSL line go through the sync process and subsequently log into the internet line.

If you are fine to keep a wired connection, then it will help rule out wifi drops also. I suggest to check the link on the first reply because it (hopefully) will guide you through some easy troubleshooting steps that will usually confirm where the issue is. 

I will do a few tests in the next days and will post my findings here. Hopefully we will be able to indentify and solve the issue. Thank you guys for helping.

[Dieselboy]

I don't think this is the issue because I have never had this same problem in the past and I've been using this modem for years on the same connection.

Maybe the internet provider has done something but having used the same modem for years could be an issue.

Often, internet providers try and give the absolute FASTEST ADSL download speed, at the cost of reliability and stability.
Copper line length from your modem port to the exchange as well as line quality (eg noise from nearby cables or poorly terminated connectors) translate directly into ADSL sync speed.
Every telephone socket within your premises that is an extension of the single copper line that comes into your home MUST have an ADSL filter attached if there is an analogue device attached to the telephone line there. Not only that, but the filter must actually be working.

So if the line in its present state is say for example capable of 16,000kbps and your ISP is aiming to sync at this absolute maximum then I will expect regular sync drops and ADSL retraining. This will be an internet outage while this goes on and the modem will usually signal this with a flashing LED. In cases where I have provisioned ADSL for customers main internet service in the past I will call the help desk and ask them what other profiles they have that can be provisioned from their side as a target sync speed. If 16,000 is the maximum, then I will ask them to drop it down a bit, maybe to 12,000 or 10,000 which should get about 10mbps internet download speed instead of the 16mbps download speed that would have been achieved with the maximum but also incurred outages.

If you have telephone extensions throughout the home then I would disconnect the extension (if possible) from the master socket and connect the ADSL modem directly into the line (sometimes it's just the faceplate that you can unscrew but sometimes it's hard-wired in so might not be possible). If the modem is the only thing connected you can sometimes get away with not using a filter there, which can be useful if you suspect the filter is faulty. They do go faulty over time. I had this same issue with my grandmas place. The master socket was in the kitchen and it is not possible to connect anything there because it would literally be in the way on the kitchen floor. There is a hard wired extension and this costs me 1-2mbps.
The other thing is the filters. If just one is going faulty then what you might find is as soon as someone picks up a telephone (goes off-hook) the internet speed will suffer or drop out entirely and may not come back until the phone is back on-hook.

The reason for the filter being an absolute requirement if using telephones or alarm systems that use the telephone line or any other system that can be described as a telephone even emergency calling buttons is that the "filter" separates the 0-4khz frequency of the analogue voice bandwidth from the +4khz higher frequency bandwidth of the ADSL internet. Basically, the filter connects into the phone line and provides 2 ports, one for telephone and one for internet. These are low pass filter and high pass filters. There must be low to no noise on the ADSL side so it does not interfere with the high frequencies of the ADSL signalling. A little bit of noise / hissing is usually OK on the telephone side when there is no internet but any noise will impact the line itself.

The telephone line is literally 2 thin wires. And over that pair, is providing separate voice and internet, so it's easy to see how noise can severely impact the higher frequencies of ADSL internet.

Anyway, hope the above helps. The ping tests will help you pinpoint where the issue is occurring.

[Andryu]

Changing the network to as can be seen in the pic bellow seems to have fixed my issue. Two days now that is like that I haven't managed to replicate the issue. I will keep testing and let you know if anything else comes up. Also I have ordered a new switch, a cisco one, to replace the cheap one I got for future proofing 🙂