Skype offers a service that allows you to make a phone call from a PC to an ordinary phone. This means that the voice call must pass through both the Internet and through a telephone network. Discuss how this might be done.

This is done through Voice over Internet Protocol. Voice over Internet Protocol is used to transfer voice communication over the internet. The voice data is sent through the Internet, where it reaches a gateway that bridges the Internet with the telephone network. The data is then reconverted into voice when it reaches its destination. This allows the Internet and phone to be "connected."