Day 30: Layered Model Applications

The benefits of a layered model are as follows:

• It helps with the design of protocols, because each layer has a standard function and a standard interface for communication with other layers.

• It allows products from different vendors to work together, allowing for collaboration in design and competition between manufacturers of compatible components.

• It allows the technology of one layer to improve without affecting other layers.

• It provides common terminology to teach, learn, and discuss networks and network protocols.

Table 1-2 compares the OSI seven-layer model and the TCP/IP model.

Table 1-2. OSI Seven-Layer Model and TCP/IP Model

Layer 2 of the OSI model, the data link layer, is made up of two layers: the upper logical link control (LLC) layer, and the lower media access control (MAC) layer. The Ethernet protocol operates at the data link layer as well as the physical layer of the OSI model.