Dear community,

We finally got connected to fiber (rural area in Germany) and I was finally excited to disconnect my Deco System from the 4G router under the roof and connect it to the fiber. Unfortunately I was not able/capable to use the Deco via PPoE, it actually did not work with any of the three different router I have. But thats not the problem, after receiving the stock router recommended by the ISP I was instantly connected to the fast world of optical communication. 

This I thought at least :( 

I realized pretty fast that the Deco System only achieves a suspicious and rather contant 87-90 Mbps (up and down). For context here my rather simple setup:

Fibertwist P2110 --> Fritzbox 7530 --> Deco XE75 Version EU1.0  ~~ 2 additional XE75 (Backhaul 6Ghz)

legend: --> = cable connection, ~~ = wireless

This is what I did after this dicsovery:

1. Logging in directly to the ISP recommended router and performing a speedtest I received 100% of the purchased up- and download rate!  Good
2. Replacing the lan cable between Master Deco and router to ensure Gbit capabilities and not accidently running on a100Mbit one . I tried several high cat cables. No change.
   1. I even purposely tested with an obvious low quality cable und the deco app instantly told me that I have a problem and should consider replacing the cable. 
3. With the quality cable attached I checked the router. In the network overview a Gbit connection to the Master Deco is shown. 
4. I switched the mode in the deco back and forth between ap mode and router mode. no change
5. I deactivated in router mode SIP and or UPNP , which I found in some older threats here in the forum, No change. 
6. After some days of tinkering I reset the whole network, even replaced the master deco. No Change
7. Tried a minimal approach without satellites. No change.
8. Today I even rolled back the firmware to 1.4.0. (In the old setup with the 4G router I received in very rare occasions speeds >100Mbps) no change
9. All speedtests were performed with a cable to the master Deco or the ISP router.

I am currently at a loss and appreciate any further suggestions!

Kind Regards

Swensons