Also known as VoIP.

In the same way that copper telephone wires were co-opted for use by computers, the Internet Protocol was co-opted to carry telephone calls. Neither were designed for the purpose and therefore both faced technological limitations. Voice over Internet Protocol describes the transmission of telephone calls on the IP network. This was initially challenging, as IP works on a ‘best effort’ principle and sends traffic in a random stream of ‘packets’, later reassembled at destination in the correct order. Voice and video packets must arrive contiguously or they are garbled. This problem was overcome by various techniques including SIP: Session Initiation Protocol facilitates VOIP calls and is commonly used when you make a call over the internet.