The Layered Architecture & Reference Models.

A reference model is a conceptual blueprint of how communications should take place. It addresses all the processes required for an effective communication and divides them into logical groupings called layers. When a communication system is designed in this manner, it is known as a hierarchical or layered architecture. The most common Internetworking Models are OSI Reference Model, TCP/IP Model, and DoD Model.

Below are the advantages of Reference Models / layered architecture:

• Reduces complexity and accelerates evolution. A vendor may concentrate its research and development works on a single layer without worrying the details of other layers, because changes made in one layer will not affect other layers.
• Ensures interoperability among multiple vendors’ products, as vendors develop and manufacture their products based on open standards.

Explanation: It divides the network communication process into smaller and simpler components, facilitating component development, design, and troubleshooting.
It allows multiple-vendor development through the standardization of network components. It encourages industry standardization by clearly defining what functions occur at each layer of the model. It allows various types of network hardware and software to communicate. It prevents changes in one layer from affecting other layers to expedite development.