When a user logs onto Skype, for example, the Skype server knows the IP address of the computer they are using. As the user’s contacts log on, the Skype server, knowing each user’s IP address, can route communications between these parties over IP. Audio conferencing systems can be configured within an organisation and can route audio over TCP/IP. Google Talk Skype Yahoo Windows Live Messenger These common examples used for instant messaging all have voice capabilities too with options for providing audio conferencing with multiple parties. Voice over IP (VOIP) is also commonly used for conversations over the internet using TCP/IP. Both instant messaging and VOIP are possible because each device that connects to the internet must do so with a unique IP (Internet Protocol) address. |