MAPI Messaging Application Programming Interface. AMicrosoft Windows interface.
MDF Main Distribution Frame. A wiring arrangement that connects outside lines on one side and internal lines from exchange equipment on the other.
MDSC Modular Digital Shelf Controller. Part of some telephone processor subsystems.
MEDIA CARD A Media Card is used for memory backup on some telephone systems.
MEGASTREAM This is the brand name for BT’s portfoliio of digital leased lines, or private circuits.
MEMORY DIALLING Memory dialling, short code dialling and abbreviated dialling are essentially the same and allow you to dial numbers faster, and with greater accuracy.
MEMORY PROTECTION Memory protection is a backup for the system programming i.e. abbreviated dial codes in case of a power failure. There are various ways to achieve this protection and it may involve additional equipment such battery back-up. The length of protection can vary depending on location requirements from as little as one hour to several days.
MESSAGE WAITING INDICATION This usually takes the form of a flashing LED which lights up to tell you someone tried to call while you were away from your phone. You can then recall that extension with the use of a code. Message waiting is sometimes indicated by a different dial tone when you try to make another call.
MESSAGING Messaging allows extensions to leave messages on other handsets with displays. These can be from a pre-programmed list or can be to give additional information i.e. “Away from office. Back on Thursday”.
MIS Management Information System. The software and hardware required to manage an ACD operation. Some systems provide a number of real time, sophisticated displays, giving ‘real time’ information required to manage the ACD operation or call centre effectively. The MIS also stores call records to provide historical data in report form.
MMI Man Machine Interface. Any procedure which allows a human operator to access and operate a system.
MODEM A device that modulates and demodulates signals transmitted over communications facilities. It is used to allow digital signals to be sent over analogue lines.
MSIF Modular Shelf Interface. Used to control communications between the processor and telephony interfaces on some telephone systems.
MSN Multiple subscriber numbering allows several numbers to be assigned to each ISDN channel so that you can have different numbers for different extensions and devices such as modem, fax, alarm, pdq etc.
MTBF Mean Time Between Failure. The period of time that a system or device can be expected to work before a disabling fault occurs.
MTTR Mean Time To Repair. The average time required to return a faulty device or system to service.
MULTIMEDIA A combination of two or more media (i.e. voice, data, still image, video).
MULTIPLEXER Multiplexers are control devices which allow information to be sent along ISDN channels in a structured way so that bandwidth can be used effectively. It enables more than one signal to be sent simultaneously over one physical channel.
MUSIC ON HOLD Music on hold is played to a caller while they are holding for a busy extension or to be transferred. It reassures the caller that they are still connected. Internal music on hold can be rather irritating so many systems allow independent music sources such as tapes and CDs to be attached. There is a variety of music now available that is not subject to copyright, negating the need to pay performing rights.
