I would think it consists of layer 7. It knows nothing of lower layers. Layers exchange information via parcels that meet a standard. Layers do not communicate with each other but operate as clearing houses. The whole thing is an electro-chemical factory that has developed thru natural Selection to meet the current challenges of survival.
But then again, how do I consciously know this ?
7) Application : Provides different services to the applications
6) Presentation : Converts the information
5) Session : Handles problems which are not communication issues
4) Transport : Provides end to end communication control
3) Network : Routes the information in the network
2) Data Link : Provides error control between adjacent nodes
1) Physical : Connects the entity to the transmission media
cool bananas ... greg