A number of protocols have been developed to enhance the Internet architecture and improve support of applications like audio, video and interactive multimedia conferencing. Introduced below are the RTP, RTCP, RSVP and RTSP protocols. These real-time oriented protocols are designed to be used over both multicast or unicast network services. Since many real-time applications can conserve network and server resources by using IP Multicast, the special requirements and characteristics of IP Multicast have been considered in the design of these protocols, such as scalability, multicast routing, and accommodation of large numbers of receivers and heterogeneous receivers. Following the discussion of these protocols for real-time multimedia, protocols for reliable IP Multicast are considered.
Reliable delivery is required by many real time and non-real time applications.
For unicast IP services, error correction and detection in the TCP layer provides reliability. For reliable multicast, new approaches to tracking acknowledgments and detecting and correcting errors have been developed, since an IP Multicast sender may have thousands of recipients. Inc. All Rights Reserved.