Layered protocols

1.Name the seven layers of the OSI Networking Reference model, from the lowest to the highest.

2.List 2 advantages and 2 disadvantages of strictly conforming to a layered networking standard, such as the OSI/ISO networking model.

3.Data encryption of network traffic can, arguably, be employed in a number of layers of the OSI/ISO Reference model. If you were to employ encryption in exactly 2 layers, which layers would you choose, and why?

4.A system uses an n-layer protocol hierarchy. Applications generate messages of M bytes each. At each of the layers, an h byte header is added. What fraction of the network bandwidth is filled with headers?