I have CCTV in bedroom and modem is in living room and had a old hdmi cable running up but that broken and was told to buy these AV1000 TL-PA 7017. 
 

I've put plugs in nearest wall socket to modem and CCTV and connected Ethernet cables and pressed paired button and they've connected up ok.

only issue is it won't let me update firmware as I'm getting this in screenshot.

wouldn't bother me but since I've connected these TP-links I've been having issues with WiFi and everything buffering or taking ages to load and I'm on symmetry 900mb fibre broadband and I turned to-links off and WiFi was running good again. 
 

need this sorting out asap