Virtual Conferencing Glossary

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Scan converter - A device used to convert the computer video output to a television representation, or vice versa. This device must perform the appropriate scaling to convert between square pixels and rectangular pixels.

Scrambler - A device used to electronically alter a signal so that it can only be viewed or heard on a receiver equipped with a special decoder.

Serial host - A device, such as a videoconferencing codec, that is connected to a serial host port communicating over a point-to-point link. To a serial host, the MAX appears to be a cable or DCE (Data Communications Equip-ment).

Serial host port - The V.35, RS-499, or X.21 port on the MAX.

Serial host port module - A module on the MAX that connects to a serial host through its serial host port.

SNMP (Simple Network Management Protocol) - Standard for retrieving and transmitting management information (configuration, control, performance, monitoring etc). Information is formatted according to MIBs (Management Information Base).

Speed matching - Can be selected if you require some sites to be connected at difference speeds than others. You must select collaborates in the speed section along with this.

SQL - SQL is a language used to create, manipulate, examine, and manage relational databases. Because SQL is an application-specific language, a single statement can be very expressive and can initiate high-level actions, such as sorting and merging data. SQL was standardized in 1992 so that a program could communicate with most database systems without having to change the SQL commands.

Standard compression algorithm - An algorithm convention for compression of a video signal. Adherence to standards allows communication among a wide variety of videoconferencing systems, though not with the same clarity as two similar systems using a proprietary algorithm. H.320 /H.323 are the most widely accepted standards in use today.

Standards - You will often hear people referring to “standards” when talking about videoconferencing. Standards are simply the technical specifications that underlies videoconferencing. H.320 is the name of the standard that applies to videoconferencing over ISDN. H.323 refers to videoconferencing over computer networks including LANs and the Internet.

Streaming - Streaming is a term that is used interchangeably with webcasting. You can view conferences , seminars, corporate meetings and other business presentations over the Internet in "real time". Streaming technology allows you to listen or view a file on your PC through a web-browser that has a media player plug-in such as 'Microsoft Media Player' or 'Real Networks Real Player'. With streaming, an audio and/or video file is broken down into smaller pieces with pieces of the file sent through gradually whilst the file is still downloading so that you can start listening and/or viewing the file without having to wait for the entire file to download at once.

Streaming cam - A Streaming Cam pushes a live stream of images simulating that of a video camera rather than a frame from a video camera being captured at a fixed interval and then posted on a server.

Switch - A device that establishes, monitors, and terminates a connection between devices connected to a network.

Switching - The process of setting up a connection between an input and an output. It allows a subscriber to establish communications with multiple parties by sending their address to the switch, which will then attempt to make a connection.

Switch type - The type of ISDN network you are connected to. This information is available from the ISDN provider and provided to the buyer when purchasing an ISDN line.

Switched-56 - Switched 56 service allows customers to dial up and transmit digital information up to 56 Kbps in much the same way that they dial up an analog telephone call. The service is billed like a voice line-a monthly charge plus a cost for each minute of usage. Nearly all LECs and IXCs offer switched 56 service and any switched 56 offering can connect with any other offering, regardless of which carrier offers the service.

Synchronisation - The process of orienting the transmitter and receiver circuits in the proper manner in order that they can be synchronized . Home television sets are synchronized by an incoming sync signal with the television cam-eras in the studios 60 times per second. The horizontal and vertical hold controls on the television set are used to set the receiver circuits to the approximate sync frequencies of incoming television picture and the sync pulses in the signal then fine tune the circuits to the exact frequency and phase.