What technology allows telephone calls to be made over the internet?

The correct answer is VoIP, which stands for Voice over Internet Protocol. VoIP technology enables users to make voice calls using the internet rather than traditional telephone lines. This innovative method converts analog voice signals into digital data packets that can be transmitted over the internet.

One of the key advantages of VoIP is its ability to reduce costs, especially for long-distance calls, since it utilizes existing internet infrastructure. Additionally, VoIP services often come with various features such as video calling, voicemail, and call forwarding, enhancing the overall communication experience.

Other options like ISDN relate to digital transmission over circuits but are not based on internet technology. DSL is a type of internet connection but does not directly pertain to voice calls over the internet. PSTN, or Public Switched Telephone Network, refers to the traditional circuit-switched network that connects landline calls, which contrasts with the internet-based functionality of VoIP. This makes VoIP the superior choice for modern telecommunication needs, emphasizing its relevance in today’s digital landscape.