M

Mainframe
A mainframe is a large-scale computer system. Mainframe computers are powerful and attach to networks and high-speed peripheral devices, such as tape drives, disk drives, and printers.

Managed Elements
Managed elements are network resources controlled and managed by SNMP, such as devices, applications, communications lines, or databases.

Management Information Base
This is an SNMP database that lists information objects relevant to each managed object. A managed element's MIB has its own set of information objects. The management application's MIB is a compilation of MIBs of all individual managed elements.

Management Information Services (MIS)
MIS is the traditional name of a department responsible for a company network or computing infrastructure.

Manager
A manager is a collection of complex SNMP applications and databases, running on a central network management station, that monitor and control a group of SNMP agents.

Massively Parallel Processing (MPP)
MPP is a high-speed architecture that uses many separate CPUs (up to 200) to run the same program. Unlike SMP, each CPU of an MPP system has its own dedicated memory. This approach makes MPP applications harder to program, but prevents most memory bottlenecks. See symmetric multiprocessing.

Media Access Control (MAC)
MAC refers to the method used to gain access or control of a network's physical media (cabling) for sending information across the media. A MAC address is the address of a network interface card (NIC), and is synonymous with the frame address.

Media Access Control (MAC) Address
A MAC address is another term for hardware address or NIC address. A MAC address is hard-coded into the NIC.

Media Access Unit or Multistation Access Unit (MAU)
The definition of MAU depends on the type of LAN involved. In Token Ring, MAU is a multistation access unit. In Ethernet, it is sometimes referred to as a media (or sometimes medium) access unit. MAUs are a type of hub.

Megahertz (Mhz)
One hertz is one cycle of a sine wave per second. One million hertz (MHz) is 1 million cycles per second.

Message Digest 5 (MD5)
MD5 is a one-way hash algorithm that takes a message and converts it into a fixed string of digits called a message digest. It is used to create digital signatures.

Method
Methods are active capabilities of an object. They often represent verbs. For example, one method of an object representing a database command may be Execute.

Methodology
Methodology refers to the actual procedures used to implement a process, the specific tasks, methods, and tools necessary to accomplish each phase.

Milestone
A milestone is the point at which one project phase ends and another begins. It is the target date for the completion or start of a phase.

Million (Mega) Bits per Second (Mbps)
Mpbs is used to describe the speed of a communication link. For example, 10 Mbps means that 1,000,000 bits are traveling down a media every second.

Mirroring
Disk mirroring is a method of simultaneously writing information to a hard drive while backing the same information up to a second disk. One disk controller is used to write to two hard drives.

Modem
Modem is a contraction for modulator/demodulator. Modems are used to convert binary computer information into signals suitable for transmission across a telephone network.

Modulation
Modulation is the process of modifying the form of a carrier wave (electrical signal) so that it can carry intelligent information on some sort of communications medium. Digital computer signals (baseband) are converted to analog signals for transmission over analog facilities (such as the local loop). The opposite process, converting analog signals back into their original digital state, is referred to as demodulation.

Multidrop
Multidrop refers to a data communication configuration where multiple terminals, printers, and workstations are located on the same media, and only one can communicate with the "master" at a given time. Multidrop is a form of unbalanced communication.

Multicast
Multicast refers to sending information to a group (multiple) of computers at the same time. Similar terms are unicast (sending to one computer) and broadcast (sending to all attached computers).

Multiplexer (MUX)
A multiplexer (MUX) is computer equipment that allows multiple signals to travel over the same physical media. Multiple signals are fed into a multiplexer and combined to form one high-speed output stream. This output stream of information consists of all the combined inputs to the multiplexer.

Multiplexing
Multiplexing is technology that allows multiple signals to travel over the same physical media.

Multipoint Distribution Service (MDS)
MDS is wireless, line-of-sight broadband technology for Internet access. Methods of MDS include MMDS, also called multichannel multipoint distribution system or wireless cable, and LMDS. MMDS runs on both licensed and unlicensed microwave channels, in 6-MHz increments; each channel can transfer from 27 Mbps to 1 Gbps. LMDS is a nonmobile technology with a range of 3 to 5 km, and can deliver from 38 Mbps to 2 Gbps. A single LMDS node can serve up to 80,000 customers.

Multiprocessing
In a multiprocessing environment, multiple computers are used to process a single application.

Multipurpose Internet Mail Extension (MIME)
MIME is an extension of SMTP that supports the exchange of a wide variety of document files via an e-mail system.

Multistation Access Unit (MAU)
A MAU is a Physical Layer device that combines the functions of repeaters and hubs, and is used to implement Token Ring networks. A MAU repeats a signal from the output of one node to the input of the next, allowing signals to flow in a logical ring. Some MAUs used in Token Ring networks have an active component (relay) to maintain ring integrity by bypassing an inactive node.

Multitasking
The ability of a computer to execute multiple processes and applications at the same time. Although a computer with a single processing unit can only execute one instruction at a time, a multitasking operating system can load and manage the execution of multiple applications by allocating computer processing cycles to each application in sequence. The perceived result is the simultaneous processing of multiple applications or tasks. There are two kinds of multitasking: preemptive and cooperative. With preemptive multitasking, the operating system is in charge and manages system resource allocation and task scheduling. With cooperative multitasking, applications are in charge and share resources.

Multithreading
A thread is a process within an application that executes a specific operation. A computer capable of multithreading is one that supports multiple threads, essentially allowing applications to multitask within themselves. Network Basic Input/Output System (NetBIOS) NetBIOS, an API, provides a uniform set of commands for operations between a client and server across a network.