@olivier483 

Hello, only the main Deco gives out IPTV, and there is only 2 ethenret ports, and one of them need connect to the modem to get internet;

If you have multiple IPTV devices, you can order a unmanaged switch, and connect it to the second port of the main Deco and connect the IPTVs to the switch; 

Note: Theoretically, the unmanagsed switch will receive and transfer the data with VLAN tag to the connected devices. 

Below are some unmanaged switch from TP-Link:

https://www.tp-link.com/business-networking/unmanaged-switch/

May it help and have a good day. 

@mdreds 

Hello, the IPTV and internet VLAN ID are different. 

For IPTV, please follow the instruction below to set it up. 

https://www.tp-link.com/support/faq/2421/ 

Note: For the IPTV mode, please choose the correct one given by ISP. 

For the internet VLAN, you can enable VLAN ID and check 802.1q tag to make the internet work. 

https://www.tp-link.com/support/faq/2465/

With the VLAN enabled, the internet will work, and the connected devices do not need internet VLAN ID. 

For the IPTV feature, cause it is tagged by VLAN ID, if you have multiple IPTV, you can use the unmanaged switch, which will forward and receive the tagged data. 

May it help.