No joint operation with Entertain interference

I have the Triple + Adapter elected to more than one device to connect to a power outlet. Including a decoder for Entertain IPTV.
The Telekom uses a separate VLAN (Virtual LAN) to decouple the data transfer of the decoder from the rest of the network.
Unfortunately, it turned out not support the internal switch of the Triple + this feature. Even cheaper switches can not support this function, however, move in the price 20 Euro area.

For a product with total cost of 140 euros, however, I expect this basic function even if the operation is promoted by IPTV.
Thus, one would have to explicitly acquire an additional PowerLan adapter for an IPTV decoder which would drive the total cost to about 200 euros.

For normal operation only with personal computers and game stations, the device is certainly suitable, but the manufacturer of the internal switch charged almost 50 euros in addition.
A Gigabit Switch with the necessary VLAN support is, however, to have been for 30 euros.