I'd love some input on the following problem. It is not modem related, as we just now got another modem from the ISP to see if the problem was resolved. It was, for a week. Then it started again.

Setup: Current Modem/router Inteno dg-201-r1a and previous Telewell (cannot remember what model), newest firmware on both, problem occurred with the latter a bit more frequently. Two PCs, both WIRED to the router. One iPhone, sometimes also a Windows phone, connecting Wireless. One SmartTV (LG), connecting Wireless. One Chromecast, also Wireless. Internet: 100 Mbit down and 20 up. We can use 2 pcs at the same time, or a pc and a TV or Chromecast. Never all devices at the same time.

It seems to be the case that the wireless environment (network+internet) in our home crashes completely whenever we are handling any kind of larger traffic, even the kind that should be OK for this modem, like downloads. This means any bigger download can break down our wireless environment, even if the download occurred wired (on my PC on steam, for example). That means our wifi can go down if I download a big file on wired, yes. I'm not 100% that this is the cause, but it seems to be a systematic occurance whenever wifi goes down - a lot of data got transferred, either from the internet or locally.

It also never tries to buffer anything if this happens with the TV (streaming PC->TV using Serviio). It just either works, or work for a bit and then suddenly our wifi will go poof (again, all our wired stuff will still work flawlessly). Can be in the first minute or after 4 hours. I recognize that this modem is not meant for streaming HD stuff wirelessly to our TV, or even wired, yet it works 70% of the time. I'd expect it to be laggy or buffering if it cannot handle the traffic, yet none of that: Wifi just goes down, done, gone, disappeared, evaporated. It's out of the air and stays out of the air forever until I take off electricity from my modem and plug it back in.

Mostly I'm confused to why the Wifi would die if I'm downloading anything on my wired connection about 20% of the time. Thinking it was a faulty modem was a great theory until it turned out to not be the case and now I'm not even sure sinking 150-200 euro my own modem/router will fix it, whatever is causing it.

Some details, perhaps, of import:

Internet DOES drop out completely (even on wired), for a brief period of time, usually between 1 to 10 minutes. This happened this morning, and the wifi cut-out happened just now. It happened almost every day on the old modem (Telewell), but only once that we're aware of on the Inteno (once in 3 weeks, now).

We have suffered DDOS attacks in the past (6 months ago), but we were using a different router and different OSes at that time. We should have a different IP now and router logs have always been clean afterwards (I kept a paranoid eye on that). Router logs of the Telewell were devoid of any useful information concerning the issue, and this Inteno doesn't seem to have logs (trying to find & enable them).

Thanks for any ideas.