Network Layered Architecture

To tackle with the design complexity most of the networks are organize as a set of layers or levels. The fundamental idea of layered architecture is to divide the divide the design into small pieces. The layering provides modularity to the network design. The main duty of each layer is to provide offer services to higher layers, and provide abstraction.  The main benefits of layered architecture are modularity and clear interfaces.

The basic elements of a layered model are services, protocols and Interfaces.

A service is a set of functions that a layer offers to another layer (usually to upper layer).

We know that protocol is a set of rules. Here the protocols are used to exchange information with a peer layer. Peers means layers at same level. The protocol consist several rules that deals with the content and the order or structure of the messages exchanged.  All the data from one layer to another either upper or lower layer pass through the corresponding interfaces. Suppose we have an n layered network then, layer-n of one machine take conversation with layer-n on another machine. Here layer-n protocol define the rules and orders.

Five Layered Network

Why layered architecture is preferred in computer network design?

Layered architectures have several advantages. Some of them are,

• Modularity and clear interface
• Provide flexibility to modify network services
• Ensure independence of layers
• Management of network architecture is easy
• Each layer can be analyzed and tested independent of other layers

Next : OSI Layers

Previous :  Topology tree and mesh

Index :   Computer Networks and Communication online coaching