tailieunhanh - 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. | 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. Conferencing Standardization at the IETF In the past working groups such as MMUSIC did some work on conferencing . 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