Hello guys,
I want to buy high end vdsl2 modem for gaming to be bridged to openwrt how to choose modem and does gigabit port affect gaming? My speed is 70mbps download and upload 15 mbps currently i have zte h168n vdsl modem do i need to buy high end vdsl2 modem or h168n zte is enough?
Typically a gigabit port will only offer relatively little over a 100Mbps ethernet port if the achievable rate stays below the gross 100 Mbps fast-ethernet can deliver; in your case 70/15 VDSL2 is well below what 100/100 ethernet can deliver. The only advantage is that on a gigabit link the data transfer to/from the router from/to modem will be a tiny bit faster, and I mean a tiny bit compared to the latency your packets will gain over the VDSL and internet part of the path.
IMHO, unless your current modem has problems and/or can not be configured for bridge mode there is little reason to switch...
is there something can improve gaming beside qos (cake.sh) and fullconenat ?
Practice, man, practice! 
Sorry could not resist...