Conferencing between two sites is termed “Point to Point” and is the most frequently used method. It only requires equipment at each site and the network of choice. If more than two sites require a simultaneous conference, this is termed “Multipoint” conferencing, and an additional specialised piece of equipment is required, called a “Multipoint Control Unit” or MCU. Some videoconferencing CODECs can support limited multipoint working (e.g. up to 4 sites). Generally, MCU’s are very expensive and are rented from service providers just for the duration of a conference. Educational and research organisations which are entitled to register with Vscene have the use of Janet’s MCUs.