Internet speed fluctuates a lot?

My parents recently signed a contract with Telekomv with a maximum performance of 100 Mbit / s. I have now downloaded a game on my Xbox and noticed that the speed fluctuates a lot. Within seconds, the speed changes from 90+ Mbit / s to 0.1 Mbit / s and everything in between. The speed is not constantly high. What can that be? I'm connected via Devolo Dlan.

In addition, I don't get higher than about 40 Mbit / s on the cell phone via WLAN.

Is the d-lan adapter plugged into a power strip?

No. There's also nobody else online who needs a high bandwidth. Only my cell phone and the Xbox, although I only write here on Girlfriend on my cell phone while the download is in progress

Of course, I took the measurement on my mobile phone before downloading it

Powerline is not as stable in most cases, hence the fluctuations.

Have you ever tried directly on the router via LAN cable to the XBOX?

It does not work. Too far

But I couldn't manage 30 Mbit / s on the cell phone via WLAN. I know that Wi-Fi is susceptible, but I still think that's not much, as I shouldn't have any source of interference in the house. It was barely 1 meter away.

There's no such thing as impossible. I connected my desktop via LAN cable which goes over the roof ^^ xD

On the mobile phone this is really a little bit, theoretically it should be around 12.5Mb / s download if you get a full 100Mbit / s. Which router do you use?

Then give me such a long cable

We have a Speedport router from Telekom.

The problems could have several reasons, but no one here can tell you exactly why. It would be best if you call Telekom directly, only they can really help you.

Here: https://www.amazon.de/...01AO44XT0/

What else I would think of, maybe look again in the router settings, or if necessary retrofit with Speed Home Wi-Fi. What exactly is there in terms of data on the Xbox (possibly with a picture).

First measure via LAN cable. And for better Wi-Fi, I recommend a Fritzbox, which also saves you money, much cheaper after just one and a half years than renting the Speedport and much better.