RADVISION术语表

Glossary (M)

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MAC (MEDIA ACCESS CONTROL)
A system of rules used to move data from one physical medium to another.

MASTER
The side in communications which initiates and controls the session. The “slave” is the other side that responds to the master’s commands.

MCU (MULTIPOINT CONFERENCING UNIT)
A device that manages a multipoint conference by connecting the multiple sites and stations in the same video conference. The MCU can be used in conjunction with a Gateway to connect H.320 and 3G-324M video conference endpoints. The MCU combines video, audio and data streams from multiple conference endpoints into one multi-location, interactive session.

MEDIA GATEWAY
Acts as a translation unit between disparate telecommunications networks such as PSTN, Next Generation IP Networks, 2G, 2.5G and 3G radio access networks or PBX. Media Gateways enable multimedia communications over multiple transport protocols, such as ATM and IP.

MGCP/MEGACO (MEDIA GATEWAY CONTROL PROTOCOL / MEDIA GATEWAY CONTROLLER)
An IP telephony signaling protocol from the IETF. MGCP was the original protocol, which evolved into MEGACO. Both protocols are designed for implementation in IP phones and endpoints that are less expensive than SIP or H.323 phones.

MGW
See Media Gateway

MGWC (MEDIA GATEWAY CONTROLLER)
Also known as MGC, this system is used in some VoIP architectures. The media gateway controller handles the registration and management of media resources at the media gateway using MGCP or MEGACO. The media gateway controller exchanges messages with central office switches via a signaling gateway. It is also sometimes called a call agent, call controller, or softswitch.

MIB (MANAGEMENT INFORMATION BASE)
An SNMP structure that describes the particular device being monitored. Networking element typically includes Public MIB (mandatory) and Private MIB (vendor specific).

MMS (MULTIMEDIA MESSAGING SERVICE)
A mobile system application enabling message-based exchange of multimedia content. MMS messages can be generated by mobile users with handsets running an MMS client. The MMS standards are part of the 3GPP standards that enable message composition of text, voice, video and graphics.

MNP (MOBILE NUMBER PORTABILITY)
The ability of a mobile subscriber to change subscription networks within the same country while retaining original MSISDN(s).

MOBILITY
The ability for the user to communicate while moving; independent of location.

MPEG-4
A series of standards developed by the Moving Pictures Experts Group, designed to reduce the storage requirements of digital video. MPEG-4 provides the standardized technological elements for the integration of interactive graphics applications and interactive multimedia.

MPU (MEDIA PROCESSING UNIT)
A component of an Interactive Video Platform. Capable of accepting calls from video terminals, such as 3G mobile telephones, while connecting them to live or stored/streamed video content. It also has extensive media processing capabilities. The MPU can connect to multiple streams in parallel via multiple protocols and produce many video layouts.

MRCP (MEDIA RESOURCE CONTROL PROTOCOL)
A communication protocol, created by the IETF, which allows speech servers to provide various speech services, such as speech recognition, speech synthesis, etc.

MRFP (MEDIA RESOURCE FUNCTION PROCESSOR)
An IMS element that implements service media processing, such as in conferencing servers. It uses advanced DSP technologies to provide voice/video mixing, transcoding, text overlay and service announcements.

MRFC (MEDIA RESOURCE FUNCTION CONTROLLER)
An IMS element that controls one or several MRFPs. It uses SIP/IMS to interface the CSCF and various Application Servers to provide media processing services for different applications.

MSCP (MEDIA SERVER CONTROL PROTOCOL)
A protocol to control media server functions for interactive media and conferencing functions. The protocol also provides extensibility mechanisms allowing messages which are defined outside this document to be passed using the MSCP protocol.

MSISDN
The mobile equivalent of ISDN. The standard international telephone number used to identify a given mobile subscriber. The number is based on the ITU-T E.164 standard

MSML
A proposed alternative protocol to the W3C-approved CCXML and VXML for the interface between the IMS application server and the MRFC.

MSN (MULTIPLE SUBSCRIBER NUMBER)
A method of incoming call routing in which a group of phone numbers is assigned to a particular ISDN line by the telephone company. PRI ISDN lines are usually assigned multiple numbers in the US and in Europe.

MSRP (MESSAGE SESSION RELAY PROTOCOL)
The preferred IMS protocol for instant messaging (IM). This extension enhances IM, as messages flow end-to-end and not through the server chain.

MULTIPOINT
Communication configuration in which several terminals or stations are connected. Contrast with point-to-point.

MULTICAST
See IP-Multicast

MULTI-UNICAST
Transmission of duplicate data streams, one to each user. In multi-unicast, multiple users request the same data from the same server at the same time. Contrast with IP multicast, unicast.

MULTIPLEXER
A device that encodes information from two or more data sources into a single channel.