312 GlossaryLip synchronizationA function that synchronizes sound withmotion. Sound processing is much fasterthan motion processing, thus sound andmotion sometimes get out of step with eachother.MCUAn abbreviation for Multipoint ControlUnit. When connecting a MCU, a multipointvideoconference can be held.MLPData communication is also available duringcommunication of video/audio signalsbetween the videoconferencing systems.The MLP or HMLP is a protocol for datacommunication such as NetMeeting. Usingthe HMLP protocol allows faster datatransmission.MPEG4A video coding algorithm recommended bythe ISO/IEC based on the H.263+ standard.Adding some tools provides someimprovement of picture quality comparedwith the H.263+ standard. The MPEG4format is commonly used for personalcomputers, cellular phones, etc.P in PAn abbreviation for “Picture in Picture.”This is a function which allows you tomonitor your own party on a small windowon your TV monitor.QCIFAn abbreviation for Quater CIF. The numberof pixels is a quarter than one of CIF format.176 pixels × 144 linesSecondary terminalNormally, a multipoint videoconference isnot available unless the video and audiomodes and transmission rate of thevideoconferencing systems of all the sitesare the same.*1 For a multipointvideoconference the terminal that can beconnected in the same modes is called aprimary terminal, while a secondaryterminal is the terminal in which some of thefunctions are restricted since the connectionis not enabled with the same modes. Therestriction on the functions depends on theconditions described in “Notes onSecondary Terminals” under “in chapter 8Multipoint Videoconference”.For example, this system does not transmitvideo signals to a terminal that has nocommon formats but can communicate viaaudio signals. In this case, the terminal inwhich picture viewing is not available isregarded as a secondary terminal.*2 Aterminal communicated via a normal phoneincluded in the multipoint videoconferenceis also called a secondary terminal. Fordetails on secondary terminals, see “Noteson Secondary Terminals” on page 227.*1 Difference between the NTSC and PALcolor systems is permitted.*2 Receiving the video signals from thisterminal may be available with the system.SIPAn acronym for Session Initiation Protocol.SIP is a communication control protocolused for Internet telephony, instantmessaging, etc.SNMPAn abbreviation for Simple NetworkManagement Protocol. This protocol is formanagement information between themanagement station and the managedterminals.SPIDAn abbreviation for Service Profile ID.StreamingA technology that allows audio and videodata to be played back as it is downloadedfor real time viewing over a network, such asthe Internet.Sub-addressAn identification number given to devicessharing a common ISDN line.TOSInputting the information data in the TOSfield of the IP address allows thecommunication system to judge the packettransmission priority, etc. It also enableschange of path according to the types ofservice (Delay or Size).
