To understand how VoIP works and how internet calling is more efficient, we must first understand how a traditional phone line works.
Traditional phone systems depend on a technology called circuit switching. This technology has been in use for over 100 years. How it basically works is that when a call is made, a connection is established between the two parties and the connection is maintained throughout for the entirety of the call. This connection is called a circuit since it is made between two separate entities with signals being transferred in both directions. This system is called the Public Switched Telephone Network(PSTN). To understand this better, let us split up the process of making a call into the following steps:
- Picking up the receiver and listening for a dial tone, which indicates that your line is connected to your telephone carrier's local office.
- Dialling the number you wish to call. When this happens, your call is directed through a switch at the local carrier's office, and a subsequent connection is made between you and the receiver through a series of interconnected switches along the way. If you need any kind of information on this article-related topic click here whoer
- Once the connection is established, the phone at the receiver's end rings, and the receiver picks it up. Once this happens, the circuit is opened, and a conversation ensues after which both parties close the connection by hanging up. Once both parties hang up, the line is free and can be used again for other calls.
The thing about circuit switching is that the circuit is continuously open throughout the entirety of your conversation. At either end of the line, your voice is converted into a digital signal and transmitted at a fixed transmission rate of about 64 kilobytes per second (Kbps) in either direction over a fibre optic cable. That makes for a combined transmission rate of about 128 Kbps. So, if you consider that in kilobytes (KBs), that makes for 16KB of data getting transmitted every second, 960 KBs for every minute and so on. The problem with this system is that most of this data is wasted due to pauses in conversation and the fact that only one person speaks at a time and hence only half of the data contains a voice at a time. So, essentially about half of the total data is being wasted.