VIDEO CONFERENCING
VideoConferencing Networks
Integrated Services Digital Network (ISDN)
This method uses the existing telephone infrastructure to carry digital signals. The quality of ISDN conferencing is limited by the quality (or bandwidth) of the connection, varying from 64kbit/s (ISDN-1) to 2 Mbit/s (ISDN-30).
The normal bandwidth used for meetings is either 128kbit/s (ISDN-2) or 384kbit/s (ISDN-6).
One important feature of ISDN is its Guaranteed Quality of Service (GQoS), which means that if for example a 384kbit/s link is dialled then unless there is a fault condition the full 384kbit/s will be provided for the duration of the conference.
Internet Protocol (IP)
IP standards-based videoconferencing was engineered for videoconferencing that takes place on a data network without any quality-of-service standard, such as the Internet. Such networks are not intended for delivery of sensitive near real-time applications.
The data network is used for multiple purposes: e-mail, web browsing, and other activities are inter-mixed with IP videoconferencing.
The audio/video information within a videoconference is segmented into chunks by the application, encoded and compressed, put into a series of data packets and sent over the network to the remote end at constant intervals.
The data packets arrive at their destination at varying times, if at all, and often out of order. To keep the "real time" impression of an interactive videoconference, the packets must arrive, on time and in time to be re-ordered for delivery through the videoconferencing terminal.
John Boland, Chief Executive pictured presenting HEAnet's Special Criteria Award to Matija Milenovic and Shane Gonley from Athlone Community College, Co Westmeath,
HEAnet has recently welcomed its latest client, Co Kildare Vocational Education Committee (VEC) who provide a comprehensive range of education services through Kildare: 
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