Summary

The IT industry relies on a layered model rather than a flat model for design, maintenance, and troubleshooting simplicity. The OSI reference model utilizes the layered approach to define the functions of the components of each layer on the model. With each layer of the model performing its defined function, networks can operate and cooperate properly. The Transport layer of the OSI model, for instance, determines flow control and works in conjunction with positive acknowledgements and windowing to guarantee delivery of data.

The network designer must understand the client’s available technology, learn to design networks using the best methods, and oftentimes justify to the customer and network engineers his or her designs.