Real-time protocols – RTP/RTCP

This article describes the need for protocols specifically designed for real-time applications, their significant features and their desired characteristics. It briefly introduces the RTP/RTCP protocols, the most widely used protocols for carrying real-time application data. INTRODUCTION 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.