ABSTRACT
The prime objective of this book is to describe scalable networked multipoint multimedia conferencing and multistream immersive telepresence based on standards providing interoperability in multivendor and multi-product networking environments, thereby offering economics-of-scale in building large-scale global scalable networks. In this context, we have described the basic difference between point-to-point and multipoint conferencing. We have articulated the general aspects of connectivity, functional, and performance characteristics of multipoint multimedia conferencing. We have explained the third-party multipoint conferencing using proprietary non-scalable centralized controller and media bridging as implemented before creation of the standards. More importantly, all the conferencing functional entities are networked, and each of these entities can be located anywhere in the world interconnected over the network, such as the public Internet, a private network, or a hybrid public Internet and private network. The complexity of networking aspects of multipoint multimedia conferencing is explained along with session initiation protocol and session description protocol architecture. The implications of multiple media bridging and limitations of the session description protocol architecture for session negotiations in view of multipoint conferencing are provided in detail. An initial introduction of the emerging multistream immersive telepresence system, which deals with specially designed telepresence conference rooms, life-size images, media captures, encoding groups, capture scenes from different angles, and simultaneous sets is provided here. In this context, we have included third-party multipoint multimedia conferencing. This is an initial attempt by the IETF to create a centralized multiparty multimedia conferencing architecture standard using the controller as a black box to provide all conference services. At that time, there was little understanding of how to develop scalable, centralized controller architecture using the standard-based protocols/interfaces among all the conferencing service functional entities that are controlled by the controller, although it was a good start to meet the immediate market needs. We describe third-party multipoint multimedia conferencing based on RFC 3725, which has developed the best current practice for offering a centralized multiparty conferencing architecture for the following, using the session initiation protocol (SIP) (RFC 3261) call control signaling protocol: Third-Party Call Establishment, Recommendation for Third-Party Call Setup, Error Handling, Continued Presence in Third-Party Call Control, Third-Party Call Control and Early Media, and Third-Party Call Control and Session Description Protocol (SDP) Preconditions. Some examples of third-party multipoint conferencing are also provided. Finally, Third-Party Multipoint Call Control implementation recommendations are provided, along with security and drawbacks. We have articulated in detail that the scalability of the present multipoint conferencing systems is a huge problem. We then introduced the framework for the Scalable Networked Multipoint Multimedia Conferencing (RFC 5239) and Immersive Telepresence (RFC 7205) Framework, which uses the standardized conferencing systems and protocols; in fact, the presentation of all standardized conferencing systems and protocols for building interoperable functional entities and protocols. In this context, we outlined the organization of this book in different chapters, relating each one step-by-step in the context of the conferencing and telepresence framework.
