Chapter 23- Conferencing on the Internet ppt

Chapter 23

Conferencing on the Internet

Conferencing involves communication among several users. Multimedia conferencing,

including audio, video, instant messaging, whiteboard sharing, and file transfer, is a popular

service on the Internet and in enterprises. Chat rooms where users exchange instant messages

are an example of a conference service on the Internet. The collaboration tools used in most

enterprises are also examples of conferences.

Thus, conferences are not limited to traditional unmoderated audio or video conferences.

They can include all types of media and can be moderated by using floor control mechanisms.

Conferencing is an important area for enterprises with employees working in different

countries. A conference system including collaboration tools can save much money and time

by reducing the need for face-to-face meetings where attendees need to travel great distances.

However, we are still far from having conference systems that can replace face-to￾face meetings completely. That is why there is much ongoing research in areas such as

telepresence and virtual reality. The goal is to make virtual interactions as close to real ones

as possible.

23.1 Conferencing Standardization at the IETF

In the past, working groups such as MMUSIC did some work on conferencing (e.g., SDP

was designed with multiparty sessions in mind). Lately, the working groups that have been

active in this area have been SIPPING and XCON. In fact, implementers sometimes find it

confusing to have similar specifications in the same area coming from two different working

groups. Knowing the history behind conferencing standardization at the IETF will help

readers understand how the specifications coming from both working groups relate among

them.

Initially, the SIPPING working group developed a set of specifications that described

how to provide conferencing services using SIP. Coming from the SIPPING working group,

these specifications were, unsurprisingly, very much focused on SIP. Pieces needed to build a

complete conference service such as floor control and conference management mechanisms

(beyond the simple ones SIP provides) were out of the scope of this work.

The XCON working group was chartered to work on generalizing the work done in

SIPPING so that different signaling protocols (not only SIP) could be used and to specify

those missing pieces needed to build a complete conference system. The charter was limited

to centralized conferences where clients connect to a central server following a star topology.

ıa- ´ Martın´

The 3G IP Multimedia Subsystem (IMS): Merging the Internet and the Cellular Worlds Third Edition

Gonzalo Camarillo and Miguel A. Garc

© 2008 John Wiley & Sons, Ltd. ISBN: 978- 0- 470- 51662- 1