End to end reliable multicast transport protocol requirements for collaborative multimedia systems

Multi-party collaborative multimedia applications require data to be transmitted reliably and efficiently in order to provide a guaranteed quality of service (QoS). The multimedia applications can vary from distributed games and shared whiteboards to interactive video conferencing. These applications often involve a large number of participants and are interactive in nature, with participants dynamically joining and leaving the applications. In order to provide many-to-many interaction when the number of participants is large, IP multicasting is a very good option for communication. IP multicasting provides scalability and efficient routing but does not provide the reliability that these multimedia applications may require. Though a lot of research has been done on reliable multicast transport protocols, it really seems that the only way of doing a reliable multicast is to build it for a given purpose like conference control in multimedia conferencing. This paper compares some of the available multicast transport protocols and analyses the most suitable features and functionalities provided by these protocols for a facet of conference control: floor control. The goal is to find or design a reliable multicast transport protocol which would scale to tens or hundreds of participants scattered across the Internet and which would deliver the control messages reliably.