Videoconference Terminology Section
I've heard many different terms used in relation to Videoconferencing - what do they mean?
The following are some of the most common terms used in context to videoconferences:
| 128 kbps / 256 kbps / 384 kbps / 512
kbps / 768 kbps
Each of these terms identifies the connection speed (or bandwidth) that a facility's equipment is capable of supporting. The easiest way to understand the difference between the connection speeds and for you to specify your requirements is that if you require a higher quality video image you will need to specify the 'quality' in terms of the bandwidth. The higher the bandwidth - the higher the quality of the video image (in terms of resolution and frames per second) |
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| Bridge
- Multipoint Control Unit (MCU)
This is an item of equipment that enables multiple conference systems to be connected together in a single multi-point conference. Typically a conference bridge will dial-out to each of the end videoconference systems in turn connecting them to the bridge, enabling each to see and hear the other. |
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| Codec In layman's' terms the codec is the generic term given to the videoconference device that performs the processing of the audio and video signals. The term codec is an acronym with two
alternative meanings: |
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| Compression Compression works by eliminating redundancies in data. Compression can be done for any kind of file, including text, programs, images, audio, video, and virtual reality (VR). Compression can reduce the size of a file by a factor of 100 or more in some cases. For example, a 15-megabyte video might be reduced to 150 kilobytes. The uncompressed file would be far too large to download from the Web in a reasonable length of time, but the compressed file could usually be downloaded in a few seconds. For viewing, a decompression algorithm, which "undoes" the compression, would have to be used. |
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| IP Internet Protocol - usually identifies that a call may be placed via a broadband internet connection as opposed to a dial-up ISDN connection. Whilst the associated costs for such calls may be lower than that for ISDN, the mechanisms for ensuring the quality of the connection may vary unless routed via an Internet Service Provider that can guarantee the QoS. |
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| ISDN Integrated Services Digital Network - this is the predominant communication protocol that has been used to establish digital dial-up connections between Videoconferencing systems. Whilst the associated costs for such calls are higher than that for IP, the mechanisms for ensuring the quality (QoS) of the connection are guaranteed - provided that the calls are not routed via a low cost network provider. |
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| QoS
Quality of Service |
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| Multi-Point (MP) Multi-point is where you are able to connect more than two sites in one videoconference. In some instances the equipment at each site may not be capable of supporting multiple connections, in this instance a 'bridge' is required that connects all sites at the individually required communication link speeds. |
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| Point-to-Point
(P-P)
Point-to-point is the direct connection of two sites in a videoconference, just in a normal telephone call connection the two parties may be on different networks and may route the call via a third-party operator or service provider. |
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| Scan converter This is the device that is used to connect your PC screen output to the videoconference system enabling the image from the PC to be viewed during the conference. |
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| Transcoding This function is usually performed by a bridge (MCU) and enables videoconferencing systems connecting at different speeds (data rates) and/or with different Codecs to be connected together overcoming connectivity interworking issues. |
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