What is Computer Network………
A computer network is the infrastructure that allows two or more computers (calledhosts) to communicate with each other. The network achieves this by providing a setof rules for communication, called protocols, which should be observed by allparticipating hosts. The need for a protocol should be obvious: it allows differentcomputers from different vendors and with different operating characteristics to‘speak the same language’.
This chapter introduces the fundamental concepts of computer networks. Wewill first look at constituent network components and various network types, andthen describe a reference model for network protocol architectures which we willexpand upon throughout the rest of this book. We will also discuss the role ofinternational standards and major standards organizations.
After reading this chapter you should be able to:
· Describe the general characteristics of a computer network.
· Understand the role of the major components of a computer network.
· Distinguish between different network types and understand their properties.
· Appreciate the relevance and importance of standards, in general, and the OSImodel, in particular.
· Describe the role and functions of each of the OSI layers.
· Use sequence and state transition diagrams to interpret and describe protocols.
· Appreciate the wealth of knowledge available on communication networks.