Hi, 

I recently installed a Deco P9 system which is working very good. Our setup is a 50 Mbit DSL connection going into a AVM Fritbox router (7490). The router acts as modem mainly (as Wireless is disabled) and for the DECT telephones. The ethernet ports are used to connect to the Deco P9 system and ohilips hue system 

The only challenge I am having is the internet based TV service from our provider 1&1. We have three different hardware decoder boxes:

1. 1&1 TV Box new: Sagecom DIW 387 - running perfectly
2. FireTV Stick - running perfectly
3. 1&1 TV Box older but still up to date and supported: Abox42 M30 - not working

For the third option I upgraded to the latest firmware, did a factory reset and tried wireless and wired connection ( speed is above 20 Mbit). Result is always the same: picture stays black and no sound. But some data must be received as I can always see the episode/movie that is currently running and this is always up to date. Telefon call with 1&1 technical support didn't help at all - their suggestion is that the two (3. Abox 42 M30) boxes are defect - strangely they work when I connect them directly to the fritzbox router we are using. 

Any ideas what setting in the Deco system could cause this beahvior or any idea what else might be the root cause? Thanks for your help!