Commutator is an adjective that is used to describe that which commutes : it substitutes, modifies, replaces or changes something. As a noun, the idea of a switch can refer to different devices.
According to DigoPaul, a switch can be a device that allows an electrical current to change conductor. To accomplish this goal, the commutator makes the electrons follow a different path.
The operation of these switches is similar to that of the switches. While switches are responsible for disconnecting an electrical circuit, switches cause current to pass to another conductor to connect a different circuit.
In the field of telephony, the machine that is responsible for connecting different telephone lines is called a switch. Also known as a switchboard, the switch allows two points to be linked through different nodes. In other words, the switch determines the path that establishes the communication between two users, said path being “busy” until the communication in question ends.
Switching in the context of a telephone network is not a simple action, but consists of different stages, and all of them must be successful for communication to take place. In the first place, there is the connection request, which must be approved to proceed to the call establishment ; then begins the stage in which the data transfer occurs between the different nodes; finally, the connection release must be executed.
Let’s look at some of the advantages of using a switch for telephone communication:
* The transmission is carried out in real time, something essential for this type of communication. At present, it is possible to establish a connection to transmit data audio and video in real time, something that we see in so – called video calls ;
* Throughout each session, the nodes participating in the communication have exclusive access to the resources, and this guarantees an acceptable level of quality;
* there is no containment. This means that since the circuit is established, the nodes can transmit the data at the maximum speed allowed by the medium, and they must not share the time of use or the bandwidth;
* Once the circuit is established, it is not necessary to spend time carrying out calculations and routing those nodes that are among the main ones, since the switch allocates a specific physical circuit to each communication session. In this way, intermediate nodes receive a single route for packets, both incoming and outgoing.
Of course, the switch also has certain disadvantages, such as the following:
* the start of communication is not immediate, since it is necessary to dedicate time to the first stages, so that it is not possible to transmit the data until they have been passed;
* while the parties are not using the resources assigned to them, they are wasted;
* the communication path is fixed and this prevents it from being readjusted according to the needs of each connection;
* If an intermediate node has a fault, the whole circuit is dropped and the process must be started again.
For computing, a switch is a logical digital element that serves to interconnect different sections of the network. The switches carry data from one segment to another according to the destination MAC address of the different frames on the network.
Thanks to such a switch, various sections of a network can be connected to merge. Because they only transmit the data to the segments in which there is a recipient, they allow to improve the security and the performance of the so-called local area networks.