This is more of a public service announcement rather than a request for help now :-)

I'm on BT in the UK and they use PPPoE for there full fibre connection. I recently moved onto their 500mb package and was happily measuring 500-515mb download using the Deco app when using the Bt supplied Smart Hub 2 router and my Deco in a double-NAT setup.

I wanted to take the opportunity to get rid of the Smart Hub and and plug my M5 into the ONT directly.

Everything worked fine (after a bit of ipv6 setup tweaking) except the download speed measured on the Deco app dropped from 500-515mb to 400-450mb.

I spent weeks trying to figure out why this is the case - it looked like the Deco was just not as good as the Smart Hub at dealing with the PPPoE.

However, I shouldn't have worried, I plugged in a windows 10 PC directly via Ethernet to the second port on my main deco and using the Ookla app confirmed that I was indeed still getting the 500-515mb speeds.

I proved this out by doing alternate speed tests on my windows 10 PC and the Deco app on my phone and got:

App - 430

Win10 -500

App - 400

Win10 - 505

App - 450

Win10 - 515

If anything the app should be quicker as that runs on the actual router - I'm assuming that the Deco M5 hasn't quite got the CPU grunt to run the PPPoE connection as well as running the on-board speedtest resulting in a lower measurement.

TL;DR - the deco app seems to under-report the download speed on PPPoE connections and don't spend weeks worrying about it :-)