All currently existing telecommunication networks can use two types of communication to provide the required functions - switching channels and (or) packets. What is it and how do they differ from each other?
Let's start with how circuit-switched networks work. They appeared earlier than their analogs with dial-up packages, therefore, which is not surprising, they are easier to implement. A striking example of a network that uses channel switching is the telephone line. Obviously, in order for two subscribers to start communication, it is necessary to establish a connection between them. The initiating subscriber dials a number, which, in fact, is a command to equip the telephone exchange (PBX) located between them to properly connect two lines - from the initiator and from the responder (we take an example when subscribers are served by one station). Previously, mechanical probes on the simplest position sensors were used for this ,then, with the advent of digital solutions, the implementation has changed, although the principle has remained the same. Switching channels provides subscribers with an independent line, which remains assigned to them until the end of the communication session. The advantages are obvious: high reliability, no need to transmit control packets. However, this connection method with an increase in the number of subscribers becomes too wasteful, since the number of channels is physically limited. Even an attempt to solve this problem by using seals is only a temporary measure, defined by an interim solution. In addition, channel switching has one significant drawback - the communication line is busy all the time, even if there is no exchange of information between subscribers. For instance,during a telephone conversation, you can hang up next to the device and go about your business - the channel will remain reserved for them until you receive a signal to disconnect.
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In general, switching is switching something, changing states. In network technology, it forms a route for passing data. The peculiarity lies in the way it is organized. Switching should not be confused with routing, whose task is to find the optimal route.