Coral fungus

Sleet plays havoc with the fungi. Most of the ground level ones are turning to mush. I found this strange looking fungus part way up the trunk of a young tree (probably birch, I can't remember now). It is in a series of wavy tiered layers, a bit like a brain, with the exposed edges showing a coral-like structure. The bulk is white in colour but there are bands of beige.

I'm afraid I have no ideas what it is so I'm calling it 'coral fungus' until further notice. Grateful for correction if anyone can identify it.