Does fresnel node corresponds to fresnel-equations?

In principle BSDF manual,specular is set to ((ior-1)/(ior+1))^2/0.08 to get realistic result.So does this imply that reflection amount (percentage of incident light) is only determined by ior and light angle on a flat surface ? If so,how should I set up nodes for diffuse,reflection and refraction ?Although all dielectic material has refraction,sometimes I just want to ignore it for simplicity.In this case,how should I remove the part of refracted light and just do diffuse and reflection ?

Edit:I search wiki and it says the amount of reflection and refraction is determined by Fresnel coefficients.https://en.wikipedia.org/wiki/Fresnel_equations From the simple normal case,R=((n_1 - n_2)/(n_1 +n_2))^2..just plug fresnel into surface the result seems to be it.But I am not very sure.Some materials distinguish fresnel reflection and specular reflection. https://download.blender.org/documentation/bc2012/FGastaldo_PhysicallyCorrectshading.pdf

Edit:In practical,when we consider unpolarized nature light,the the reflection coefficient is just average of R_s and R_p..Or we even use Schlick's approximation..So the amount of relection and refraction is clear.Diffuse is a particular case of subsurface scattering,so it should belong to refraction.And then how much does diffuse take in refraction ?