What could be the reason for router disconnects under heavy load? (Overheating?)

[flexy]

I am on 300MB fiber with a Huawei HG8247H router/ONT and the net is generally working fine - minus the occasional but rare disconnects which may happen with any ISP.

Yesterday however I run into an issue which I could reproduce a few times:

I used the Elite Dangerous downloader which happened to download at maxed out speed, showing me at times 36-40MB/s. Every 1 or so minute into the download, I lost connection to the internet. So each time, I rebooted the router, then had to wait several minutes until I got the yellow warning in Windows removed and the net was accessible again. NORMALLY when such a thing happens I always know/say "it's on their end", and it may well be, but this time I could reproduce this several times. Started download, waited a minute....BOOM!...net not reachable. The router lights itself didn't indicate any problem.

There are two possibilities:

* The router is overheating due to heavy load? While it was not "super-hot", the router is normally "quite warm", so this is a possibility. It is in an entertainment center/closet, but of course the vents etc. are not covered. I am in Spain so it can get quite warm/hot at times.

* The router (Linux based) is internally "overloading" ie. crashing, because of the speed and possibly many parallel connections?

Unfortunately I can't log into the admin interface of the router (anymore) since the ISP changed the PW of all their routers and doesn't want people to log in, otherwise I would check logs or something.

Anyway, what I did now was make some sort of stand from a spare 120mm fan, with the fan now blowing air up underneath the router, like a notebook cooler. I couldn't test whether this works since I didn't see the same speeds today using the Elite downloader when I tried.

Anyway..is this common that some routers disconnect at max speeds and load? I never had this problem before, eg. with bittorrent...but now thinking about it, I think I actually had on occasion but thought it's some issue at the ISP which "just" happened to happen at the time when I was downloading something...

 

[Elixer]

I am on 300MB fiber with a Huawei HG8247H router/ONT and the net is generally working fine - minus the occasional but rare disconnects which may happen with any ISP.

300Mb I assume?
That router should be able to handle 900 Mb, so, doubt that it couldn't handle the speeds. (This one, right? http://m.huawei.com/enmobile/enterprise/products/network/access/pon-one/hw-371813.htm)

Maximum power consumption: 18W, Temperature: 0℃～+40℃
Was it hotter than that?

When it crashes, yeah, that is what happens, it disconnects for a bit, while it reboots.

Really too bad you can't look at the logs.
From the manual:

Internet access failure
l
The user terminal or the loop line is faulty.
l
The PON port is faulty.
l
The data configuration of the upper-layer
device is incorrect.
l
The PON board on the OLT is faulty.
l
The optical path is faulty.
l
The board or port on the ONT is faulty.
l
There are network attacks.
l
The WAN port fails to obtain the address.
l
The ping operation with the IP addresses of
the ONT WAN port and the ONT fails.
l
The WAN MAC address of the ONT
defaults to 000000000002.
l
The NAT function is disabled on the bound
WAN port.
l
The LAN port on the ONT is a bridge
Ethernet port, but the PC connected to the
LAN port fails to obtain the IP address
allocated by the upper-layer network

Which basically you can't test most of these, you need to call up the ISP so they can remotely test it.

 

[KingFatty]

Usually I'd say you have identified how to test for temperature by using a fan, but it sounds like the speed situation is preventing you from seeing if the fan prevents overheating.

So, what about the opposite kind of heat test? Try to overheat it by turning off the fan and see if the problem reproduces?

 

[Genx87]

Does the download quit? Or do you just lose the ability on other machines to reach the internet?

 

[JackMDS]

Or, may be your ISP is controlling the system these way.

 

[flexy]

Does the download quit? Or do you just lose the ability on other machines to reach the internet?

Both...the connection to the internet goes down.

 

[flexy]

Maximum power consumption: 18W, Temperature: 0℃～+40℃
Was it hotter than that?

Yeah that's the one. Ok, the +40℃ is a joke. It can easily get 30-35℃ here in the midst of Summer, and the router is in a closet and of course by itself gets "quite warm", I am just guessing the router itself and the air around it was easily +40℃. Still testing whether the fan has improved things. Maybe I should download some linux ISOs or something.

 

[flexy]

UPDATE:

So I can reproduce this, again, downloading some 4GB ISOs from a fast FTP server.

I can now almost exclude my router, the router is now BARELY hand-warm and sure not overheating. (With the fan on now).

The internet goes out again, but the router login-interface is still up and router LEDs also not indicating a problem.

The problem seems to ONLY appear when I absolutely max out my speed, eg. when I download something and it reaches 35MB/36MB (which is rare enough), but low and behold...BOOM! yellow exclamation mark. I waited some time whether it reconnects by its own, but didn't so I rebooted the router. And 30 seconds after that, net was available again.

I also did a tracert when the net was down, I only get two hops, to my router (192.168.1.1), then to my actual internet IP (which I guess is the OLT [?], the box where the fiber connects I assume), but then nothing beyond that.

So do I have reason to believe this is something on their end?

Maybe some odd, malfunctioning throttle function on their side where when someone reaches the absolute maximum speed attainable it blocks/kicks someone? I have no explanation really.