CHAPTER 4 - Data Communication Networks

Abstract

This chapter discusses the various forms of data communication networks and the types of communication channels that have an influence on the network design. With data communication networks, connections are organized on the principles of point-to-point (PTP) connection, even though other network structures are available. As the data is in digital form, it may be stored and processed en route by computers in a technique known as store-and-forward (SAF). While point-to-point is defined as the method of direct communication between two points, store-and-forward is defined as a method of communication in which the messages may be received at intermediate routing points and stored. The messages are then transferred directly or with further network points with interim storage, each in accordance with its own address. In the case of SAF, there is no direct connection between the distant points when they are so-called communicating, but the messages are stored in the network nodes and are retransmitted in the channels only when such a channel has free time to accept the messages. Store-and-forward systems can provide means of efficiently exploiting the communication channels by ensuring smooth and continuous flow of data.