How to prevent gurgling or water coming back to shower from basin

[Mr_T25]

When using my taps on my basin I sometimes get back pressure or gurgling / water coming up the shower tray waste pipe.


I recall reading somewhere that there is a system that prevents this or air venting or something something. How does one usually prevent back flow or water coming up the shower tray trap when using the basin and closing the taps?

 

[just pumps]

Make sure all pipes are clear so water flows freely.