With a network the user must explicitly log into a machine explicitly submit jobs remotely, explicitly moves files around and generally handle all networks management personally. To reduce the design complexity, most networks are organized a series of layers or levels. Each layer built one above the other. The name of each layer number of layers, functions of each layer cliffers from network to network. The purpose of each layer is to offer services to higher layer. Network software is highly.
Protocol Hierachy: - A protocol is an agreement between the communicating parties on how communication is to proceed. To reduce their design complexity, most networks are organized as a stack of layers or levels. Each layer is kinel of virtual machine, offering certain services to the layer above it. That is the rules & conventions used in the conversations collectively known as a protocol.