Internet telephone system is a category of hardware and software that allows us to use “Internet” as a transmission medium to make long distance telephone calls. It provides free phone calls to anywhere in the world to users who have free or landline internet access.
Internet telephony refers to the use of the public Internet network for voice transmission. That is, it allows the subscriber of an Internet Service to use his computer to make long distance calls. The quality of this telephone service is not at all with the direct telephone connections so far.
We can make telephone calls over the Internet in two ways as follows:
1. In this way, we use our computer and special hardware as well as software to make calls so that one can communicate through the PC.
2. In the second form, often referred to as Internet Telephony, where a phone call is made as it normally is through a regular phone, except that the voice call is routed over the Internet instead of the regular phone service.
Internet telephony generally reduces the cost of making long distance phone calls. The revolutionary part of using the Internet to make phone calls from your PCs is the price. Which is virtually equal to zero or free. Here, the user pays only the Internet charges, which are very nominal, such as in the case of browsing the web or sending an email. The user does not need to pay for the phone call itself.
Here a user can make calls to any part of the world. Internet telephony uses the Internet Protocol (IP) which allows computers to communicate with each other anywhere in the world that has at least a basic Internet connection.
In today’s market, there are various software available that facilitate functions such as Skype, Gtalk, Cool Talk, NetMeeting, etc. Many other applications also come bundled with the web browser and other standalone products. Internet telephony products are sometimes referred to as IP Telephony, Voice over Internet (VOI) or Voice over IP (VOIP). It is transported over the Internet instead of the public switched telephone network (PSTN). This provides the flexibility to send voice calls, FAXes, SMS, etc.
Basically three types of Internet telephone systems are used. These are, software-based VOIP, physical IP phones, mobile and embedded VOIP. The main disadvantage of Internet telephony is that the service will be interrupted if there is a power outage.