Using layered protocols
Reasons for using layered protocols :-
In a layered model each layer is defined separately. Thus, the design problem is broken up into smaller and manageable pieces. Another advantage is it makes protocol designers to specialize in one area (or layer).
When changes are made to one layer, it reduces the impact on the other layers. For example, protocol in one layer can be changed easily without if affecting higher or lower layers. If the models was not layered and consisted of a single layer then any change affects the entire model.
The layered approach divided a big more complex tack into several smaller tasks where each small task is performed by one layer. This makes it much easier to learn and understand the concept of each layer and the model.
The layered approach is useful for proper organizing and handling of communication. It also provides a standard programming interface between two layers.
It is the most important reason for using a layered model. A layered model provides a guideline and framework not a rigid standard to be used by the various vendors when creating their products. This is important for interoperability between the various vendors products hat perform different data communication tasks.