Abstract
Real-time protocols cover specific needs by applications with real-time characteristics. Real-time applications, such as voice over IP (VoIP), videoconferencing applications, video on demand, continuous data applications, and control and measurement applications have specific requirements from the lower layers, mainly in terms of packet loss, delay, and jitter. Traditional transport protocols such as TCP and UDP have been designed for general use and are not specialized for such specific purposes. In particular, real-time protocols have to be able to deliver high throughput, handle multicast, manage the transmission quality, and be friendly to the rest of the traffic, and, more importantly, to the congestion-sensitive TCP traffic.
Key Terms in this Chapter
Packet Loss Rate: Packet loss rate is defined as the fraction of the total transmitted packets that did not arrive at the receiver.
Delay Jitter: Delay jitter is defined to be the mean deviation (smoothed absolute value) of the difference in packet spacing at the receiver compared to the sender for a pair of packets.
Multimedia Data: Multimedia data refers to data that consist of various media types like text, audio, video, and animation.
Quality of Service (QoS): The ability to provide specific guarantees to traffic flows regarding the network characteristics, such as packet loss, delay, and jitter experienced by the flows.
TCP (Transmission Control Protocol): A connection- oriented, reliable protocol of the TCP/IP protocol suite used for managing full-duplex transmission streams.
NVP (Network Voice Protocol): A pioneering network protocol for transporting human speech over packetized communications networks.
UDP (User Datagram Protocol): A connectionless, unreliable protocol of the TCP/IP protocol suite used for sending and receiving datagrams over an IP network.
Internet Engineering Task Force (IETF): The organization comprised of a large open international community of network designers, operators, vendors, and researchers concerned with the evolution of Internet architecture and the smooth operation of the Internet.