packet switched vs circuit switched networks
Packet-switched Vs. Circuit-switched Networks
Circuit-switched and packet-switched networks are types of telecommunication networks. This Buzzle article explains and compares these two types of networks.
- Step 1: To communicate a message from one point to another, the first thing that we need to do is to connect them. This is done by logically establishing a circuit between the two points. In this circuit, some components are dedicated while some are shared.
- Step 2: Now we have to actually send the message across from one point to another. Mostly, a full-duplex connection is established for this. In the circuit-switching technique, we send either an analog or digital signal depending on the nature of the network.
- Step 3: Once the message has been sent, we have to terminate the connection. This is done by sending signals to free the resources.
- The shortest possible path that can be taken to reach the final destination.
- The availability of the next free node through which the packet can travel.
Circuit-switched Networks | Packet-switched Networks |
The entire message is passed. | The message is broken down into small parts called packets. |
The message is passed by establishing a dedicated communication link between them. | There is no dedicated communication line. The individual packets are passed independently through intermediate nodes by the shortest route available. |
Only one message passes through any instant. | The communication line is shared by several packets by waiting in a queue. |
There is lesser overhead while communicating the message. | Each packet has a header that contains the necessary routing information. Hence, overheads are associated during transmission. |
The transmission of message happens comparatively faster. | Sometimes delays can occur while the message is being transmitted. At the receiving end, these packets are then rearranged in their proper sequence (this information is contained in the headers), and the entire message is constructed. |
Traditionally, voice data has been sent over a packet-switched network. Circuit-switched networks are used in Public Switched Telephone Network (PSTN), which is the old kind of telephone system to transmit voice signals. | Earlier voice data was not sent over a packet-switched network. But now it is used in VoIP (Voice Over Internet Protocol). [VoIP is a service in which you can use the Internet to make phone calls.] |
Sending binary data is not feasible over a circuit-switched network. | It is more feasible to send binary data over a packet-switched network. |
If a particular part of the message is damaged, the whole file has to be resent. | If a particular part of the message is damaged, only the damaged packet has to be resent. |
If there is a "dead time" or "silent time" when no communication is happening, the resources are locked and the communication line cannot be used by another sender. | When no communication happens in this case, the resources are not locked up and the communication line can be used by another sender. |
If a dedicated circuit is not required, a circuit-switched network may not be economical. | A packet-switched network may be more economical when you don't require a dedicated network. |
It is more reliable than packet-switched networks as there is no possibility of packets being lost or arriving out of order. | It is not reliable as there is a possibility of packets being lost or arriving out of order. |