Application Of Video-meeting System In The Long-distance Teaching

Originally, enterprises and communications service providers deployed packet networks primarily for handling data traffic and not for real-time IP communications. Technical barriers initially hampered the use of packet networks for real-time communications. For example, packet networks were not designed to guarantee the sequential delivery of packets and packets could be lost. In addition, the time of delivery of packets was dependent upon the amount of packet traffic being transmitted over the network. For real-time communications, it is critical that the packets associated with a specific voice or video communication be transmitted in the correct sequence and in a timely manner. Early attempts at real-tune IP communications solved these technical problems by using proprietary solutions developed by individual vendors. However, proprietary solutions from different vendors meant that different vendor products could not inter-operate with one another. To enable the global deployment of real-time IP communications networks, industry standards and protocols were developed to promote interoperability of real-time communications over packet networks. H.323 is currently the most widely deployed industry-wide protocol for real-time IP communications. H.323 was developed by a team of computing, telephony and networking experts under the direction and auspices of the International Telecommunications Union (ITU-T), a United Nations organization, with the goal of specifying a universal real-time standard that would ensure interoperability of all packet-based networks and products. H.323 provides the technical framework for developing standards-compliant products and systems for real-time voice and video communication over packet networks. All components of an H.323 compliant network (including terminals, gateways, gatekeepers and conferencing bridges) usethe H.323 protocol to communicate. Today, H.323 is the standard of choice for the builders of real-time IP communications solutions for enterprises. The ITU-T is continuously enhancing H.323 and publishing new versions to support the evolving requirements of next generation packet networks. The widespread acceptance of industry protocols and standards for IP communications has enabled the deployment of packet networks for real-time communications by ensuring interoperability and is facilitating the migration to IP communications.