How Telephones Use VoIP
VoIP, which stands for “Voice over Internet Protocol,” is the industry name for Internet telephony. The Internet Protocol is the standard that creates the Internet. Another usage of IP as an abbreviation for the Internet Protocol that you may have seen is “IP address.” That is the name of the data addressing system of the Internet and shows how “IP” is used to indicate Internet technology. This brief guide explains how the voices in a telephone call get channeled over the Internet.
- History | Before broadband, the Internet did not have the speed or capacity to carry interactive telephone conversations. Private local area networks did have that speed, and this is where voice and video applications were first used. The H.323 Protocol, published by the International Telecommunication Union in 1996, created standards for transmission over local area networks, primarily for video conferencing.
- Development | The H.323 standards were adapted for use over the Internet once it achieved the necessary capacity with broadband. The standard is called “Packet-Based Multimedia Communications Systems” and defines transmission of any audio or video data over networks. The main challenge for VoIP is to process, send and reassemble a sound signal almost in real time. Early PCs were not able to work quickly enough to perform all that processing, and any attempt to replicate a voice would have resulted in delays.
- Method | Voice and video transmissions are called “streaming” because it seems that a constant flow of information is being sent. However, the VoIP program on the sending computer converts the voice into a series of zeros and ones. As a given length of numbers is compiled, they are sent out in a packet. The receiving computer converts that packet of numbers back into a sound wave and plays it through a speaker. As telephone calls are interactive, both ends of the connection will be sending and receiving data packets at the same time.
- Problems | Even though the Internet is now very fast, packets do not always follow the same route and some many be held up or lost. In traditional Internet transmissions, the receiving program “buffers” packets, which means it holds onto incoming data for a little while in case packets arrive out of sequence. If a segment gets lost on the ay, the receiving program notices and sends a request for that chunk to be re-transmitted. VoIP programs don’t have time to buffer or re-transmit data, so any packets that get lost will result in gaps in the conversation, or even dropped calls.
- VoIP for Phones | Miniaturization enables computer chips to be integrated into any device, such as a telephone. Internet telephony companies can provide you with a telephone handset for your home that operates exactly like a regular landline phone. The handset contains a computer chip with the VoIP software embedded on it. This means that it is not necessary to operate a computer in order to connect to the Internet. Wireless telephony further expands the implementation of VoIP.