The Layered Troubleshooting Approach

Networks are based on the Open System Interconnection (OSI) model of networks, which is a layered architecture used to design networks compatible with all types of operating systems. The OSI model contains seven layers, which are organized in the order of their role for facilitating data transfer. In addition to the OSI model, another model that is widely used as a standard for internetwork communication is the Transmission Control Protocol/Internet Protocol (TCP/IP) model. This model has a four-layered architecture, and each layer corresponds to one or more layers of the OSI model. The functions of these layers are similar to those performed by the layers of the OSI model.

Because most networks are based on the layered architecture of OSI or the TCP/IP model, the troubleshooting approach applied to such networks is called the layered troubleshooting approach. Using the layered approach, you can isolate and troubleshoot problems pertaining to a specific layer. As a result, other layers are not affected, and troubleshooting is carried out on only that area of the network where the problem has occurred; the rest of the network functions without any interruption. In addition, the layered troubleshooting approach allows for easy and quick identification of the type of error or problem.

The layered troubleshooting approach provides various advantages as compared to the general troubleshooting methods. The following are the main advantages of the layered troubleshooting approach:

• Sequential analysis and identification of the problem

• Easy identification of the possible problem areas, because the function of each layer is predefined

• Facilitation of improvement of network performance