types of video conferencing systems

types of video conferencing systems
There are several types of videoconference depending on:
Type of network on which the information travels. In this classification we find 2 types of videoconference:
Videoconference on ISDN. For the realization of ISDN videoconferences (ISDN) in huddle room it is necessary to have lines of this type which is not usual. Being lines dedicated to videoconference traffic and being a direct channel between the participants, the connection speed once the videoconference is established is fixed and does not usually fluctuate, which guarantees a minimum of quality throughout the development of the event. It is advisable to have at least 3 ISDN lines (128Kb * 3 -> 384Kb of bandwidth) to have a good user experience. Nowadays there are very few videoconferences in which this type of connection is used due to its cost, low quality and the need to have such ISDN lines. The meeting room by videoconference located in the Computing Service has this type of ISDN lines as well as the necessary equipment to make videoconferences of this type if necessary.
Videoconference over IP networks. For several years it has been the most used system for videoconferencing, given that Internet connection speeds, especially between centers such as universities, are sufficiently high and stable to replace ISDN connections. It is usual to make IP videoconferences from 768Kb to 2Mb depending on the type of connection of the participating centers offering a very high quality audio, video and data. All the video conferencing rooms video conferencing services offered by this service have IP video conferencing equipment with connection speeds of up to 4MBs.
System or protocol used to carry out the videoconference. There are several ways to establish a videoconference that range from:
Videoconferencing with desktop applications such as ISL, Adobe Connect, Skype, Polycom PVX, Google Talk, etc. This type of systems do not usually use standard protocols or codecs and the quality offered is usually very low. They fit well for daily videoconferences. The videoconference service of the UA provides services for this type of videoconferences using Adobe Connect.
Desktop videoconference. Collaborative tool

conference room video conferencing equipment such as Polycom, Tandberg, ezTalks etc. They are videoconferencing systems that do use communication protocols (H323, H320, SIP) and standard audio and video codecs (H263, H264, AAC) and that are usually implemented in dedicated videoconferencing hardware. Normally all the organizations of the university area have equipment of these characteristics which guarantees interoperability and quality. All videoconferencing rooms offered by this service have equipment of these characteristics.
Dedicated videoconferencing equipment
Number of participating sites. According to this classification we find:
Point-to-Point Video Conferencing. They are videoconferences in which only 2 sites intervene. It is not necessary to have any additional equipment to make videoconferences of this type in meeting room conference call equipment.
Explanatory image of a point-to-point videoconference
Multipoint videoconferences. They are videoconferences involving more than 2 sites. In this case, it is essential to have a team that acts as the central unit (MCU) which everyone calls. This team is responsible for distributing the image and sound of everyone to everyone.
Explanatory image of a multipoint videoconference
In this type of videoconference, we must first decide how we want the MCU to distribute the video and the audio it receives. This decision is made depending on the type of video conference and there are the following 2 options:

Presentation type. One of the sites that intervenes in the videoconference acts as the main speaker while the rest of the sites only listen or make specific and short-term interventions. This is the case of a class or a presentation where there is a main speaker (the teacher or the speaker) and several sites following his talk. In this mode, all participants see and hear only the video and audio of the site that acts as the main speaker. The MCU automatically chooses who is the main speaker by selecting the site from which audio signal comes continuously. If any of the other participating sites wants to take control of the video so that they can see the rest of the sites, you just have to start talking.